Manchester United stretched their winning run in the Premier League to six matches after Juan Mata and Zlatan Ibrahimovic secured a 2-0 victory at 10-man West Ham on Monday.
Spain international Mata struck midway through the second half at London Stadium to break the valiant resistance of Slaven Bilic's side, who played for 75 minutes a man down, before Ibrahimovic blasted in a controversial second in the closing stages.
West Ham had lost none of their previous four league meetings with United but they were dealt a big blow on 15 minutes when Sofiane Feghouli, on his first start in England's top flight, was sent off for a late tackle on Phil Jones.
United struggled to carve out many meaningful chances despite their numerical advantage - although Darren Randolph made one stunning save to deny Antonio Valencia in the first half - and the Hammers spurned a great chance to take the lead when Michail Antonio shot straight at David de Gea when clean through one-on-one.
Mata steered in a fine finish only three minutes later to compound Antonio's frustrations before Ibrahimovic secured maximum points for United, who are back to within a point of fourth-place Arsenal, having played a game more.
An encouraging start from West Ham was brought to a halt on 15 minutes when Feghouli was shown a straight red card after crunching into Jones in a 50-50 challenge close to United's area.
Referee Mike Dean gave himself time to consider before brandishing a red card that incensed the home fans and Bilic on the touchline, although the way Feghouli jumped off the turf certainly made the challenge look careless.
United failed to muster a shot in the first half hour despite their advantage, but they contrived to miss a glorious chance to take the lead 10 minutes before the break.
Henrikh Mkhitaryan turned Ibrahimovic's cross back towards the near post from the right and Randolph somehow clawed Valencia's effort from point-blank range off the line before Jesse Lingard inexplicably hit the post with the rebound.
West Ham looked a threat when they broke forward and De Gea was forced to tip Manuel Lanzini's curling effort from 20 yards away from the top corner just before half-time.
Mourinho made an attacking change for the second half, introducing Mata for full-back Matteo Darmian, and West Ham were perhaps fortunate not to concede a further advantage to the visitors when Cheikhou Kouyate escaped a card for a two-footed challenge on Mkhitaryan.
Chances remained scarce but Antonio wasted a glorious opportunity for the home side when he shot straight at De Gea after being played clean through on goal by Lanzini.
Just three minutes later, that miss was punished with aplomb. Marcus Rashford surged into the penalty area before cutting back onto his right foot and teeing up fellow substitute Mata, who curled a first-time shot beyond Randolph's left hand and into the top corner.
Paul Pogba fired a good opening wide and a Rashford shot almost squirmed through Randolph's grasp and over the line, but United made certain of the points 13 minutes from the end following another decision that left the home fan's irate.
Ander Herrera's pass fell to the feet of Ibrahimovic just inside the West Ham area and he spun and lashed the ball low into the net, with the officials failing to spot that the Swede had strayed offside.