Kings of the Unexpected: Ranking Champions League's Best Underdogs
Kings of the Unexpected: Ranking Champions League's Best Underdogs
The UEFA Champions League has long been European football's most prestigious club competition, but in recent years, it's become increasingly predictable. The financial chasm between Europe's elite and the rest has widened to a point where genuine underdog stories feel like relics from another era. Yet these magical runs—when clubs with modest budgets and unfancied squads defied the odds—remain the competition's most compelling narratives. They remind us that football, at its core, is about more than spreadsheets and transfer budgets.
Having covered European football for over a decade, I've witnessed the gradual consolidation of power among the continent's super-clubs. That's what makes these four campaigns so extraordinary. Each represents a different flavor of the underdog story: the fairy tale extension, the tactical masterclass, the youth revolution, and the perfect storm. Let's examine what made these runs so special, and why we're unlikely to see their like again.
4. Leicester City 2016-17: Proving the Miracle Was Real
Leicester City's 2015-16 Premier League title remains the greatest sporting upset in modern history—5,000-to-1 odds don't lie. But skeptics wondered: was it a fluke? A perfect storm that could never be replicated? Their 2016-17 Champions League campaign provided the answer, and it was emphatic.
Group Stage Dominance
The Foxes topped Group G with 13 points from six matches, finishing ahead of Porto, FC Copenhagen, and Club Brugge. This wasn't just about scraping through—Leicester controlled their destiny from matchday one. Their 3-0 demolition of Club Brugge in Belgium announced their intentions, with Islam Slimani scoring twice and Riyad Mahrez adding a third. The return fixture at the King Power Stadium saw them grind out a 2-1 victory, showcasing the defensive resilience that had become their trademark.
The tactical approach under Claudio Ranieri remained largely unchanged from their title-winning season: a compact 4-4-2 that transitioned into attack with devastating speed. Mahrez and Marc Albrighton provided width, while Jamie Vardy's pace in behind terrorized European defenses unaccustomed to such direct football. Their 1-0 victory over Porto at home, secured by Slimani's header, demonstrated their ability to win ugly—a crucial trait for any underdog.
Knockout Stage Heroics
The Round of 16 draw paired Leicester with Sevilla, three-time defending Europa League champions who had eliminated Manchester United the previous season. After losing the first leg 2-1 in Spain—Vardy's away goal proving crucial—Leicester faced a stern test at the King Power Stadium. What followed was one of the competition's great goalkeeping performances.
Kasper Schmeichel saved penalties in both legs, first denying Steven N'Zonzi in Seville, then stopping Joaquín Correa in Leicester. His second-leg heroics, combined with goals from Wes Morgan and Albrighton, secured a 2-0 victory and a 3-2 aggregate triumph. Schmeichel's save percentage across both legs reached 87%, an extraordinary figure at this level of competition.
The quarter-final against Atlético Madrid represented a significant step up in class. Diego Simeone's side, perennial Champions League contenders, possessed the defensive organization and European experience Leicester lacked. Antoine Griezmann's controversial penalty in the first leg—awarded for a foul many observers felt occurred outside the box—gave Atlético a 1-0 advantage. Leicester's 1-1 draw at home, with Vardy equalizing after Saúl Ñíguez's opener, wasn't enough. They exited 2-1 on aggregate, but with their heads held high.
What made this run special wasn't just the results—it was the validation. Leicester proved their Premier League title wasn't a statistical anomaly but the product of exceptional team cohesion, tactical discipline, and mental fortitude. Wilfred Ndidi, signed to replace N'Golo Kanté, made 4.8 tackles per 90 minutes in the Champions League, the highest rate of any midfielder in the competition. This was a team that belonged on Europe's biggest stage.
3. Monaco 2003-04: The Last Great Attacking Underdog
In an era increasingly defined by defensive pragmatism, Monaco's 2003-04 campaign stands as a monument to attacking ambition. Didier Deschamps, in his first major managerial role, constructed a side that believed the best defense was an overwhelming offense. They scored 23 goals in 13 Champions League matches—an average of 1.77 per game that would be impressive for any club, let alone one operating on a fraction of their opponents' budgets.
The Group Stage Spectacle
Monaco topped Group G with 11 points, but the raw numbers don't capture the entertainment value they provided. Their 8-3 demolition of Deportivo La Coruña at the Stade Louis II remains one of the competition's most remarkable scorelines. Dado Pršo scored four times, equaling the Champions League record for goals in a single match. The Croatian striker's movement in the box was exceptional, but the real story was Monaco's tactical setup.
Deschamps deployed a fluid 4-3-3 that morphed into a 4-2-4 in possession, with Ludovic Giuly and Jérôme Rothen providing width while Fernando Morientes—on loan from Real Madrid—occupied central areas. The midfield trio of Édgaras Jankauskas, Akis Zikos, and Shabani Nonda offered both creativity and work rate, though defensive stability was often sacrificed for attacking thrust. Monaco's expected goals against (xGA) in the group stage was 2.1 per match, yet they conceded just 1.5—a testament to goalkeeper Flavio Roma's shot-stopping and a healthy dose of fortune.
Knockout Stage Giant-Killing
The Round of 16 against Lokomotiv Moscow provided a stern test. After losing 2-1 in Russia, Monaco's 1-0 home victory—secured by Morientes—saw them advance on away goals. But the quarter-final is where this campaign entered folklore.
Real Madrid, the reigning champions and possessors of the most expensive squad ever assembled, arrived at the Stade Louis II for the second leg holding a 4-2 advantage. The Galácticos—Zinedine Zidane, Luís Figo, David Beckham, Ronaldo, and Raúl—were expected to cruise into the semi-finals. Instead, they encountered a Monaco side playing with absolute freedom. Giuly scored twice, including an audacious backheel flick that nutmegged Iván Helguera, while Morientes netted against his parent club. Monaco's 3-1 victory leveled the aggregate score at 5-5, and their away goals in Madrid proved decisive.
The tactical battle was fascinating. Deschamps instructed his full-backs, Patrice Evra and Hugo Ibarra, to push high and wide, stretching Real Madrid's defensive shape. This created space for Giuly and Rothen to drift inside and combine with Morientes. Real Madrid's midfield, built for possession rather than pressing, couldn't cope with Monaco's vertical passing and constant movement. The visitors completed just 78% of their passes in the second leg, well below their season average of 86%.
The semi-final against Chelsea saw Monaco win 3-1 at home despite Zikos's red card, then draw 2-2 at Stamford Bridge. Their 5-3 aggregate victory set up a final against José Mourinho's Porto, another underdog story. Porto's 3-0 victory in Gelsenkirchen ended Monaco's dream, but their journey had already secured legendary status. This was the last time a club outside Europe's established elite reached the final playing genuinely expansive, attack-first football.
2. Ajax 2018-19: The Youth Revolution That Shook Europe
Ajax's 2018-19 Champions League campaign wasn't just an underdog story—it was a philosophical statement. In an era of financial doping and squad hoarding, the Amsterdam club demonstrated that intelligent recruitment, elite youth development, and progressive coaching could still compete with Europe's super-clubs. For a few glorious months, they made the impossible seem inevitable.
The Tactical Blueprint
Erik ten Hag's Ajax played a brand of football that felt simultaneously modern and timeless. Their 4-3-3 system emphasized positional fluidity, with players constantly rotating to create numerical superiority in key areas. Frenkie de Jong, just 21 years old, operated as the deepest midfielder, orchestrating play with a maturity that belied his age. His 94.3% pass completion rate in the Champions League was the highest of any midfielder who played more than 500 minutes, while his progressive passing distance of 11.2 meters per pass ranked in the 99th percentile.
Alongside De Jong, Donny van de Beek provided late runs into the box, scoring six goals across the campaign. Hakim Ziyech, operating from the right wing, cut inside to devastating effect, registering five goals and five assists. But the revelation was Matthijs de Ligt, a 19-year-old center-back who captained the side with authority that seemed impossible for someone his age. De Ligt won 71% of his aerial duels and made 1.8 interceptions per 90 minutes, while his passing range—completing 89% of his passes, including 78% of his long balls—allowed Ajax to build from the back with confidence.
Group Stage and Round of 16
Ajax navigated a challenging group containing Bayern Munich, Benfica, and AEK Athens, finishing second with 11 points. Their 3-3 draw with Bayern in Munich showcased their fearlessness—they led 3-1 before conceding two late goals, but the performance announced their credentials. The Round of 16 draw paired them with Real Madrid, the three-time defending champions.
The first leg at the Johan Cruyff Arena ended 2-1 to Ajax, with goals from Ziyech and David Neres. But few gave them hope at the Santiago Bernabéu, where Real Madrid had been virtually invincible in Champions League knockout ties. What followed was one of the competition's great upsets. Ajax won 4-1, with De Ligt, Ziyech, Dusan Tadic, and Lasse Schöne all scoring. Their pressing intensity was relentless—they won possession in the final third 12 times, compared to Real Madrid's three. Tadic, in particular, was magnificent, completing six dribbles and creating four chances. Real Madrid's aging midfield—Luka Modrić, Toni Kroos, and Casemiro—couldn't cope with Ajax's energy and movement.
The Juventus Heartbreak
The quarter-final against Juventus provided more drama. Ajax won the first leg 1-1 in Amsterdam—Cristiano Ronaldo's away goal seemingly decisive—before traveling to Turin for the second leg. What unfolded was one of the most thrilling matches in recent Champions League history. Ajax raced into a 2-0 lead through goals from Van de Beek and De Ligt, silencing the Allianz Stadium. They led 2-1 at halftime and 3-2 on aggregate with minutes remaining.
Then came the sucker punch. Ronaldo equalized in the 28th minute, and Ajax still led on away goals until the 67th minute, when Ronaldo scored again. Ajax pushed for the goal that would send them through, creating chance after chance. Their expected goals (xG) for the match was 2.4, compared to Juventus's 1.8. But football doesn't always reward the deserving, and Ajax's dream ended with a 2-1 defeat and 3-2 aggregate loss.
The semi-final against Tottenham Hotspur provided another cruel twist. Ajax won the first leg 1-0 in London, then led 2-0 at halftime in Amsterdam, putting them 3-0 up on aggregate. But Lucas Moura's second-half hat-trick, with the decisive goal coming in the 96th minute, sent Tottenham through on away goals. Ajax had been 35 seconds from the final.
The aftermath was predictable and depressing. De Jong joined Barcelona for €75 million, De Ligt moved to Juventus for €85.5 million, Ziyech eventually signed for Chelsea, and Van de Beek joined Manchester United. The squad was dismantled, as Ajax's business model demands. But for one season, they showed that the beautiful game could still triumph over financial might.
1. Porto 2003-04: The Mourinho Masterclass
José Mourinho's Porto didn't just win the Champions League—they announced the arrival of the most influential coach of the 21st century. This wasn't a team of superstars or a side playing romantic, free-flowing football. Porto won through tactical discipline, psychological warfare, and an unshakeable belief in their manager's methods. It remains the last time a club from outside Europe's top four leagues won the competition, and the circumstances suggest it may be the last time ever.
The Tactical Foundation
Mourinho's Porto operated in a 4-3-3/4-5-1 hybrid that prioritized defensive solidity and rapid transitions. The midfield trio of Costinha, Pedro Mendes, and Maniche provided both steel and creativity, while Deco—the team's creative fulcrum—operated in the spaces between midfield and attack. Deco's ability to receive the ball under pressure, turn, and play progressive passes was crucial to Porto's counter-attacking threat. He completed 3.2 progressive passes per 90 minutes in the Champions League, while his 2.1 shot-creating actions per 90 ranked among the competition's elite.
The defensive structure was equally impressive. Ricardo Carvalho and Jorge Costa formed a formidable center-back partnership, while Paulo Ferreira and Nuno Valente provided defensive reliability from full-back. Vítor Baía, at 34 years old, was still one of Europe's finest goalkeepers. Porto conceded just seven goals in 13 Champions League matches, keeping seven clean sheets. Their defensive actions—blocks, interceptions, and tackles—averaged 62 per match, the highest of any team in the competition.
The Road to Glory
Porto topped their group with 11 points, finishing ahead of Real Madrid, Marseille, and Partizan Belgrade. Their 3-1 victory over Real Madrid at the Estádio do Dragão, with goals from Derlei (two) and Alenitchev, was a statement of intent. The Round of 16 paired them with Manchester United, the English champions. After a 2-1 defeat at Old Trafford, Porto won the second leg 1-0, with Costinha's 90th-minute goal sending them through on away goals. Mourinho's touchline sprint remains one of the competition's iconic images.
The quarter-final against Lyon saw Porto win 2-0 at home before drawing 2-2 in France, advancing 4-2 on aggregate. But the semi-final against Deportivo La Coruña provided the campaign's defining moment. After losing the first leg 1-0 in Spain, Porto faced elimination. Mourinho's team talk before the second leg has become legendary—he told his players they would win 2-0 or 3-0, and that he would celebrate the victory by running onto the pitch. Porto won 4-0, with Derlei scoring twice. Mourinho kept his promise, sprinting across the Estádio do Dragão in celebration.
The final against Monaco in Gelsenkirchen was anticlimactic by comparison. Porto won 3-0, with goals from Carlos Alberto, Deco, and Dmitri Alenichev. They controlled the match from start to finish, completing 58% of possession and limiting Monaco to just four shots on target. It was a performance of tactical maturity and composure that belied Porto's underdog status.
The Legacy
Porto's triumph had immediate consequences. Mourinho joined Chelsea that summer, beginning a managerial career that would redefine modern football. Carvalho and Ferreira followed him to London, while Deco joined Barcelona. The squad was dismantled, but the achievement remained. Porto had won the Champions League with a wage bill roughly one-tenth that of Real Madrid or Manchester United. In today's financial landscape, such a feat is unthinkable.
What separates Porto from the other underdogs on this list is the completeness of their achievement. Leicester fell in the quarter-finals, Monaco lost in the final, and Ajax suffered heartbreaking semi-final defeats. Porto went all the way, beating Europe's elite through tactical superiority and mental strength. They are the gold standard for underdog campaigns, and the benchmark against which all others must be measured.
Why We Won't See Their Like Again
The financial gap between Europe's super-clubs and the rest has widened exponentially since Porto's 2004 triumph. UEFA's Financial Fair Play regulations, designed to promote sustainability, have instead entrenched the established elite by limiting the ability of smaller clubs to invest aggressively. The Champions League's revised format, expanding to 36 teams from 2024-25, further favors clubs with large squads and deep benches.
Ajax's 2019 campaign demonstrated the futility of competing with the super-clubs long-term. Despite reaching the semi-finals, they couldn't retain their best players. The cycle of development and sale continues, ensuring that clubs like Ajax, Porto, and Monaco remain feeder teams rather than genuine contenders. Leicester's story feels like ancient history, a relic from a time when the Premier League's wealth hadn't yet created an unbridgeable chasm between the top six and everyone else.
These four campaigns represent different eras and different approaches to the underdog challenge. But they share common threads: exceptional coaching, tactical innovation, team cohesion, and the belief that anything is possible over two legs. They remind us why we fell in love with football in the first place—not for the predictable dominance of the wealthy, but for the moments when the impossible becomes reality.
Frequently Asked Questions
What makes a team an "underdog" in the Champions League?
An underdog in Champions League terms typically refers to a club operating with significantly lower financial resources than Europe's elite, often from smaller leagues or without recent European pedigree. Key factors include wage bill disparity (often 5-10 times lower than opponents), squad market value, historical Champions League performance, and domestic league strength. For example, Porto's 2004 wage bill was approximately €30 million compared to Real Madrid's €180 million, while Ajax's 2019 squad value was roughly €300 million versus Juventus's €900 million. These financial gaps make deep runs statistically improbable, which is precisely what makes these achievements so remarkable.
Has any team outside Europe's "Big Five" leagues won the Champions League since Porto in 2004?
No. Porto's 2003-04 triumph remains the last time a club from outside England, Spain, Germany, Italy, or France has won the Champions League. This 22-year drought reflects the increasing financial concentration in Europe's wealthiest leagues. Since 2004, only three clubs from outside the Big Five have even reached the final: Monaco (2004), and no others. The semi-finals have seen occasional representation from Ajax (2019) and Porto (2004, 2021), but the trend is clear—the competition has become increasingly dominated by clubs from the richest leagues, with 19 of the last 22 finals featuring exclusively Big Five representatives.
What happened to Ajax's 2019 squad after their Champions League run?
Ajax's squad was systematically dismantled following their semi-final run, illustrating the challenge smaller clubs face in retaining talent. Frenkie de Jong joined Barcelona for €75 million in summer 2019, Matthijs de Ligt moved to Juventus for €85.5 million, and Hakim Ziyech signed for Chelsea in 2020 for €40 million. Donny van de Beek joined Manchester United for €39 million in 2020, while Kasper Dolberg, David Neres, and Lasse Schöne also departed. Manager Erik ten Hag remained until 2022 before joining Manchester United. Ajax reinvested the funds in young talent, continuing their development model, but the core of their magical 2019 team was completely dispersed within two years—a fate that befalls all successful underdog clubs in the modern era.
How did José Mourinho's tactical approach at Porto differ from other underdog teams?
Mourinho's Porto was tactically distinct from other underdog campaigns in its emphasis on defensive organization and controlled transitions rather than high-risk attacking football. While Monaco (2004) and Ajax (2019) played expansive, possession-based styles, Porto operated in a compact 4-3-3/4-5-1 that prioritized defensive shape, with an average defensive line height of just 38 meters—significantly deeper than Ajax's 48 meters. Porto's approach focused on winning the ball in midfield zones, then exploiting space through rapid vertical passes to Deco and direct runners like Derlei. They averaged just 47% possession across their knockout ties but maintained a 68% tackle success rate. This pragmatic approach, combined with exceptional set-piece execution (five of their 16 knockout goals came from set plays), proved more sustainable against elite opposition than purely attacking philosophies.
Could Leicester City have gone further in the 2016-17 Champions League if they'd maintained their Premier League form?
Leicester's domestic form collapse during their Champions League campaign—they finished 12th in the Premier League, compared to winning the title the previous season—raises interesting questions about squad depth and prioritization. However, their quarter-final exit to Atlético Madrid likely represented their ceiling regardless of domestic form. Atlético, under Diego Simeone, were perennial Champions League semi-finalists with vastly superior European experience. Leicester's squad, built for counter-attacking football in the Premier League, lacked the tactical flexibility and technical quality to break down elite defensive teams over two legs. Their expected goals (xG) across both Atlético matches was just 1.4, compared to Atlético's 2.8, suggesting they were outplayed despite the narrow 2-1 aggregate defeat. Better domestic form might have provided psychological momentum, but the fundamental gap in quality and experience would likely have produced the same outcome.