Juan Mata put United ahead early in the second half of what had looked like being a frustrating night for Jose Mourinho’s side, who spurned several chances to put the tie to bed.

Paul Pogba rattled the post with a free kick and a string of other opportunities went begging as Hull dug in before substitute Marouane Fellaini rose at the far post to head home with three minutes remaining.

Southampton and Liverpool contest the other semi-final, with the first leg at St Mary’s on Wednesday.