Romelu Lukaku scored his 12th goal in 11 FA Cup games as an uninspired Manchester United beat Brighton to reach the semi-finals.

Lukaku headed in a first-half cross from Nemanja Matic, who sealed victory late on when he nodded in Ashley Young’s free-kick.

Victory maintained realistic United hopes of a trophy after Tuesday’s Champions League elimination by Sevilla, as well as their record of not having conceded a goal in this season’s FA Cup.

But Jose Mourinho’s side struggled through the second half, as Brighton had several chances to force extra-time before Matic finally put the tie to bed.