Goals from Marcus Rashford and Marouane Fellaini have earned Manchester United a 2-1 victory over West Ham United in their FA Cup sixth-round replay at Upton Park.
West Ham began the match on the front foot and they should have taken the lead after just five minutes but after Manuel Lanzini played in Enner Valencia on the left-hand side of the penalty area, he could only shoot straight at David de Gea from 12 yards.
United took their time to get into the contest but on 18 minutes, Fellaini almost found the roof of the net after ghosting into the box only to see Darren Randolph tip the ball over the crossbar.
The visitors continued to dominate possession and with 10 minutes of the first half remaining, a run from Rashford ended with the ball being played to Jesse Lingard, but his low strike was kept out by the leg of Randolph.
United did not let up before the half-time whistle but only Michael Carrick could force another effort on goal, with his left-foot volley going wide of the target.
The Hammers needed a response after the restart but it took just nine minutes for United to go in front through Rashford, who curled the ball into the top corner from just inside the penalty area after receiving a pass from Lingard.
Van Gaal's men were well worth their lead and they netted a second midway through the second half when Fellaini was perfectly placed to bundle the ball home from three yards after an Anthony Martial half-volley had been partially blocked.
United appeared to be coasting through to the last four but after De Gea pulled off a save to deny Michail Antonio at the near post, West Ham halved the deficit through James Tomkins with the defender heading home from six yards after Andy Carroll had won the ball at the back post.
The Hammers pushed for an equaliser and Carroll should have at least found the target when rising above the United defence but his header went a yard over the crossbar.
There was more drama to come as De Gea pulled off stunning saves to deny both Kouyate and Carroll before the midfielder saw a header disallowed for offside.
It was the correct decision, just, and it proved decisive as United saw out the remainder of the game to set up a last-four showdown with Everton.
