Barcelona were 2-0 down from the first leg in Italy but got off to a fantastic start, as Leo Messi played a one-two with Xavi before curling a brilliant shot past Christian Abiatti.
Messi then scored a superb second goal before half time, albeit from an offside position, to level the tie. David Villa struck a crucial third goal to put Barcelona ahead for the first time and then Jordi Alba wrapped up the win in the last minute.
