Man United started the game on the front foot but failed to get a shot on target, neither did the visitors, in the first half.
The hosts maintained the same intensity in the second half but that one vintage moment wouldn’t come until in the additional time.
Edinson Cavani found Marcus Rashford far end of West Ham United’s post and Rashford made no mistake against an empty net.
Manchester United 1-0 West Ham United.
The game is increasingly likely to end this way as the Hammers would have less than a minute to stage a dramatic equaliser.