Let's be honest, everyone loves an underdog, especially in the Champions League. That feeling when a team punches above its weight, shocks the giants, and makes a run deep into Europe's premier competition? Pure magic. We've seen a few over the years, but some stand out more than others. We’re talking about runs that defied logic, busted brackets, and etched themselves into history. I’ve covered enough of these tournaments to know when a team is just getting lucky, and when they’re genuinely building something special. Here are four of the best, ranked from great to greatest.
**The Near Misses and Shockers**
First up, at number four, we have **Leicester City's 2017 campaign**. Coming off their miraculous Premier League title in 2016, the Foxes were a story in themselves, but their European adventure was a different beast. They topped Group G with 13 points, winning four games including a 3-0 thrashing of Club Brugge and a 1-0 home victory against FC Porto. The magic continued into the Round of 16 where they faced Sevilla. After a 2-1 loss in Spain with Jamie Vardy scoring a important away goal, they powered through at the King Power, winning 2-0 thanks to goals from Wes Morgan and Marc Albrighton, securing a 3-2 aggregate victory. Kasper Schmeichel even saved a penalty from Steven N'Zonzi in that second leg. Their run ended in the quarterfinals against Atlético Madrid, a 1-0 loss at the Vicente Calderón and a spirited 1-1 draw at home, seeing them exit 2-1 on aggregate. What made it special? It was the final gasp of that incredible Leicester core – Vardy, Riyad Mahrez, N'Golo Kanté (though he left before the UCL run, his spirit was there), and Morgan – showing they weren't just a flash in the pan. Realistically, though, it was more of a continuation of their domestic fairytale than a standalone European shocker.
At number three, let’s talk about **AS Monaco in 2004**. This team, managed by Didier Deschamps, was a revelation. They finished top of Group C, ahead of Deportivo La Coruña, with 11 points, highlighted by an astounding 8-3 victory over Depor, with Dado Pršo bagging four goals on his birthday. The knockout stages were where they really made noise. In the Round of 16, they faced Lokomotiv Moscow, losing 2-1 away but winning 1-0 at home on a Pršo goal, advancing on away goals. Then came the earthquake: Real Madrid in the quarterfinals. After losing the first leg 4-2 at the Bernabéu, with Fernando Morientes scoring against his parent club, Monaco pulled off a stunning 3-1 victory at home, Morientes again on the scoresheet, to advance on away goals (5-5 aggregate). The semi-finals saw them dispatch Chelsea, winning 3-1 at home and drawing 2-2 at Stamford Bridge, sealing a 5-3 aggregate win. Key players like Ludovic Giuly, Patrice Evra, Jérôme Rothen, and the aforementioned Morientes were on fire. The final against Porto was a bridge too far, a 3-0 loss, but their journey, particularly that Real Madrid upset, was legendary. It was the ultimate "prove them wrong" narrative against the Galácticos.
**Chasing Immortality**
The number two spot goes to **Ajax in 2019**. Erik ten Hag’s side was a dream team of young talent and seasoned vets, playing some of the most exciting football in Europe. They navigated a tough Group E, finishing second behind Bayern Munich but ahead of Benfica and AEK Athens, drawing 3-3 with Bayern in their final group game. The Round of 16 saw them face defending champions Real Madrid. After a 2-1 home loss, many wrote them off. But at the Bernabéu, they delivered a performance for the ages, winning 4-1 with goals from Hakim Ziyech, David Neres, Dušan Tadić, and Lasse Schöne, knocking out the kings of Europe 5-3 on aggregate. The quarterfinals brought another giant: Juventus. After a 1-1 draw in Amsterdam, Matthijs de Ligt’s header in Turin secured a 2-1 victory and a 3-2 aggregate shocker. It felt like destiny. In the semi-finals against Tottenham, they won the first leg 1-0 in London and were 2-0 up at halftime in Amsterdam. Then Lucas Moura happened, scoring a hat-trick, including a dramatic 96th-minute winner, to steal it 3-2 for Spurs, sending Ajax out on away goals after a 3-3 aggregate. Frenkie de Jong, De Ligt, Ziyech, and Tadić were phenomenal throughout. This run was special because it wasn't just about upsets; it was about a philosophy, a style of play that captured the imagination of the entire football world. They played without fear, full of attacking flair. Honestly, they deserved to be in that final.
But the greatest Champions League underdog run, without a shadow of a doubt, belongs to **FC Porto in 2004**. José Mourinho's team wasn’t just an underdog; they were a with precision drilled, tactically brilliant machine that went all the way. They finished second in Group F, behind Real Madrid, but crucially beat Marseille twice and drew with Partizan Belgrade. Their knockout journey started with a bang against Manchester United in the Round of 16. After a 2-1 win at home, they were 1-0 down at Old Trafford in the second leg when Costinha scored a dramatic 90th-minute equalizer, famously celebrated by Mourinho sprinting down the touchline, sealing a 3-2 aggregate victory. In the quarterfinals, they comfortably dispatched Lyon, winning 2-0 at home and drawing 2-2 away for a 4-2 aggregate. The semi-finals pitted them against Deportivo La Coruña. A tense 0-0 draw at home was followed by a gritty 1-0 away win at the Riazor, courtesy of a Derlei penalty, sending them to the final. And in the final, they comprehensively beat Monaco 3-0, with goals from Carlos Alberto, Deco, and Dmitri Alenichev. Key players like Deco, Ricardo Carvalho, Maniche, and Vítor Baía were central, but the real star was Mourinho’s tactical genius. What made it the greatest? They didn't just upset big teams; they *won the whole damn thing*. No "almost," no "what if." They completed the journey, a true outsider from a non-traditional football powerhouse lifting the biggest club trophy in Europe. No other underdog on this list achieved that ultimate goal.
My bold prediction? We won't see another team from outside the traditional "big five" leagues lift the Champions League trophy for at least another 20 years. The financial gap has become too vast.