Most people watching 10-man Chelsea on Tuesday night will have assumed it was just a matter of time before Barcelona scored the goal they required, even after Lionel Messi's penalty miss.
It seemed Barcelona, and coach Pep Guardiola, thought the same. As the minutes ticked by, the defending champions kept on attacking the same way, exchanging short passes on the edge of the area, seeking a way through the white wall. Only in the very final minutes did they change tack, and then it was to throw Carles Puyol forward and pump high balls into the box. It was not so much Plan B as Plan Z, the option of last resort.
Barcelona are so used to winning there was an inability to think on their feet and recognise the need to adapt their play. This is not to suggest they were wrong to stick to their passing-game principles, it is to argue they became overly fixated on one aspect: short passes around the box. They did not need Plan B, they needed to make Plan A work effectively, as they had before.
When Barcelona needed a goal to beat a massed Chelsea defence in the last minute of the 2009 Champions League semi-final it came via a shot from outside the box, Andres Iniesta drilling the ball in from 20 yards at Stamford Bridge. The closest Barcelona came to scoring in the last 40 minutes this week was from a shot of similar distance, by Lionel Messi, which Petr Cech touched on to the post. Yet despite that they had few other shots from distance. Cech is an excellent keeper, but shots through a crowded area have a habit of wrong-footing the best through deflections.
Barcelona also failed to target their attacks intelligently, trying to go through a packed centre instead of testing the makeshift full-backs. Chelsea strung six across the back, with three midfielders ahead of them, but it meant using strikers as full-backs. Yet despite winning a penalty when Cesc Fabregas ran at Didier Drogba on the flank they rarely repeated the tactic. Time and again Dani Alves got the ball on the right facing Drogba, then passed backwards and inside rather than take the forward on. It did not help that the ball was frequently passed, slowly, to Alves' feet instead of played with pace into space ahead of him. When it was, Alves created a goal, only to be flagged just offside.
Alves looked like a player reluctant to take responsibility and he was not alone. Barcelona did not just suffer from doubt and tiredness, they lacked leadership on and off the pitch.
Barcelona 1-1 Leeds United 23 April 1975
Another famous draw from a 10-man side at the Nou Camp: Peter Lorimer put Jimmy Armfield's Leeds United ahead (they had won 2-1 at Elland Road), leaving Barcelona needing two. Gordon McQueen was sent off, but the Barcelona of Johan Cruyff and Johan Neeskens could only manage one, and Leeds reached the final.
Cologne 0-1 Nottingham Forest 25 April 1979
Having drawn 3-3 at the City Ground with the German champions, Forest had a difficult task. After a tight first half, Ian Bowyer's decisive header from John Robertson's corner put them ahead and they dug in, aided by Peter Shilton, for a famous victory.
Juventus 2-3 Manchester United 21 April 1999
Probably the greatest ever performance by probably the greatest ever United side. After drawing 1-1 at Old Trafford, United conceded two early goals in Turin to Pippo Inzaghi, but, were dragged to the final by a heroic performance by captain Roy Keane, despite a booking that ruled him out of the final. He scored the first, before Dwight Yorke and Andy Cole made it 2-3, setting up a famous final with Bayern Munich.
Villarreal 0-0 Arsenal 25 April 2006
Arsenal's only European Cup final came thanks to a goalless draw at the Madrigal. They won 1-0 at Highbury, but in the final minute in Spain, Gaël Clichy's foul gave Villarreal a penalty and the chance to take the tie to extra time. But Jens Lehmann saved from the great Juan Roman Riquelme, and Arsenal went on to face Barcelona in the final in Paris.