In the course of history, Manchester United have taken part in some huge matches. Given the calibre of the club, the team has competed at the highest levels of football, which meant crossing paths with even bigger clubs. Some of those key battles have left lasting memories for the supporters in victory or defeat.
The UEFA Champions League, in particular, offered a stern test for the Red Devils over the years. Their record as the 20-time English champions has always created the sense to dominate on a bigger scale. The Sir Alex Ferguson era brought some special moments for United fans when they, time and again, faced the biggest sides in Europe.
At the time, the usual heavyweights such as Barcelona, Real Madrid, and Bayern Munich were the dominant forces in European football. United looked to stake their claim in Europe and it meant daring to believe.
For most parts, they came up short but they took their chances when the opportunity presented itself. Ferguson did his bit in inspiring United from a team that regularly dominated English football to one that could pose a serious threat to the elite teams on the continental level.
In these three matches, United were expected to lose as they faced superior opposition but found a way to get the job done.
#3 Manchester United 4-3 Real Madrid
On 23 April 2003, Manchester United faced Real Madrid in the quarter-final of the UEFA Champions League at Old Trafford. The Red Devils had gone down 3-1 in the first leg and were heavily expected to also lose the second leg, given Madrid's super talented crop of players.
In their ranks were world class footballers such as Zinedine Zidane, Luis Figo, Ronaldo Nazario, and Roberto Carlos - all on the same pitch.
This was the sort of attacking venom that could cripple any defence in the world. Ronaldo fired Madrid ahead in the first half to make an already daunting task even harder for United.
He went on to score a glorious hat-trick in what was a pure show of class. Substitute David Beckham scored a brace with Ruud Van Nistelrooy also on target to inspire a 4-3 comeback win for the Red Devils.
However, it wasn't enough as United were eliminated 6-5 on aggregate.
#2 Manchester United 1-0 Barcelona
The stage was set on 29 April 2008 when United faced Barcelona in the UEFA Champions League semi-finals at Old Trafford. United had bravely defended to force a 0-0 draw in the first leg at Camp Nou but Barcelona were favourites to progress due to their impressive attacking options and ball handlers.
The likes of Lionel Messi, Samuel Etoo, Xavi Hernandez, and Deco were some of the bright sparks for Barcelona that United would face. Indeed it was the Catalan giants that conjured the more penetrative chances in the opening minutes of the first half.
However, United found their opening goal out of nothing in the 14th minute after a poor clearance from Gianluca Zambrotta. The ball fell kindly to Paul Scholes who took it under control before firing a 25-yard piledriver into the top right corner.
United withstood sustained pressure from Barcelona in the second half to qualify for the final.
#1 Manchester United 2-1 Bayern Munich
The 1999 Champions League final is probably United's most memorable game in their history. It is when they famously beat German powerhouse Bayern Munich 2-1 at the Camp Nou in Barcelona.
United were underdogs when they lined up against the more physically-imposing German side. It was the second time that they faced each other in the competition after being pooled in Group D.
As expected, it was Bayern that topped the group. It was a nightmare start for United as they conceded after just six minutes when Mario Basler curled a low free-kick past the United defensive wall and into the net for the lead.
The Germans dictated play and could have put the result to bed on numerous occasions. But after three minutes of stoppage time were added, substitute Teddy Sheringham got the all-important touch following United's corner at the death for the equaliser.
Shortly after the restart, David Beckham delivered another good corner into the box where Sheringham nodded the ball across the face of goal for fellow substitute Ole Gunnar Solskjaer to poke home from close range.
The favourites were stunned and well beaten on a night that United clinched their famous treble.