5 biggest deficits overturned in the Champions League Round of 16

#4 Barcelona v AC Milan (2012-13)

Lionel Messi in action for FC Barcelona against AC Milan in the UEFA Champions League

San Siro has not been a happy hunting ground for Barcelona in recent times, having been eliminated from the 2009-10 edition of the Champions League by Jose Mourinho’s Inter and then, three years later, apparently taking a big step towards the exit door against AC Milan.

Against Inter, they had the excuse that they had to take a bus all the way to Italy because volcanic ash made air travel impossible; this time around there was no such explanation as goals from Kevin-Prince Boateng and Sulley Muntari left them facing the exit door. Barca had spent the night playing with passing but no penetration and did not even have the comfort of an away goal to take home with them.

A fortnight later, back at Camp Nou, it was a very different story. Lionel Messi – who else? – set the tone for the evening as he scored after five minutes and the Argentine had the tie levelled by the interval, though only after a major scare as M’Baye Niang hit the post.

Soon after the break, David Villa had Barca ahead in the tie for the first time, but they were never safe until Jordi Alba struck two minutes into stoppage time at the end of the match.

"We will remember this for years to come," said Barca sporting director and former Spain goalkeeper Andoni Zubizarreta. And they did – until a comeback of even more epic proportions.

First Leg: AC Milan 2-0 Barcelona

Second Leg: Barcelona 4-0 AC Milan

Final Scoreline: Barcelona 4-2 AC Milan