David Moyes admitted last night that his Manchester United side produced their worst European performance since he took charge during the summer against Olympiacos.
The Red Devils had never previously been defeated by a Greek club, but goals either side of the break from Alejandro Dominguez and Arsenal loanee Joel Campbell sealed a 2-0 victory for the hosts.
Where does that result rank among other losses that United have suffered in European competition? Below, Sports Mole looks back over five other unexpected and harrowing defeats that the English champions have been dealt against opponents from the continent.
1. Sporting Lisbon 5-0 Man United
Having won the opening leg of the quarter-final Cup Winners' Cup tie with Sporting Lisbon 4-1 at Old Trafford, thanks largely to a hat-trick from Denis Law, it appeared that United were heading for the last four ahead of the second leg. Despite the three-goal cushion, though, Sir Matt Busby's side imploded inside the Jose Alvalade Stadium. Osvaldo Da Silva mimicked Law's contribution from the first leg, while further goals from Geo and Joao Morais saw the home side advance.
2. Man United 0-1 Fenerbahce, 1996
Alfredo di Stefano's Real Madrid, Diego Maradona's Barcelona and Michel Platini's Juventus had previously visited Old Trafford and all had left without having recorded a victory. In fact, ahead of Fenerbahce's visit, United had not lost any of their home European matches in 40 years. However, where more glittering players had failed, little-known Bosnian Elvir Bolic saw his shot deflect into the United net off David May 13 minutes from time and the hosts could not muster a response.
3. Man United 0-1 Borussia Dortmund
In spite of that loss to Fenerbahce in the group stages, United advanced to the semi-finals, where they met Dortmund. The first leg in Germany ended in a 1-0 win for the Germans, but much was expected of United at Old Trafford. Lars Ricken silenced the home crowd when he scored in the eighth minute, but it sparked an onslaught from Sir Alex Ferguson's team. Wayward finishing from Eric Cantona and Andy Cole in particular cost United dearly, though, as a good chance of reaching the final of the Champions League was wasted. Soon after, Cantona announced his retirement.
Manchester United - Borussia Dortmund 0-1 (1997) by sxplVII
4. Lille 1-0 Man United, 2005
A fortnight previously, these two sides had played out an uninspiring 0-0 draw at Old Trafford in the Champions League group stages. From United's point of view, it was even worse in Paris. A goal from former Tottenham Hotspur player Milenko Acimovic proved to be winner, which in turn saw United drop down to third in the standings. That was followed by a draw and a loss against Villarreal and Benfica respectively as Ferguson's team finished bottom.
2005 (November 2) Lille OSC (France) 1... by sp1873
5. Basel 2-1 Man United, 2011
A win or a draw would have guaranteed United a spot in the Champions League's knockout stages, but they achieved neither in Switzerland. Marco Streller scored early on, while six minutes from time Alexander Frei scored what would go on to be the winning goal. Phil Jones halved the deficit in stoppage time, but it was a case of too little, too late as United had to settle for a place in the Europa League.