Three sublimely-crafted goals - two from Wayne Rooney, one from Michael Owen - got United back to winning ways and moved the champions to within a point of Premier League leaders Chelsea.
West Ham were clinically put to the sword as two devastating team moves yielded Rooney headers either side of the interval, before arch-poacher Owen plundered a fine third goal within three minutes of his introduction as a late substitute.
After last Saturday's surprisingly meek surrender at Goodison Park, and with this Sunday's Carling Cup final against Aston Villa on the horizon, Sir Alex Ferguson sprang several selection surprises to face a Hammers side catapulted - for now - out of their relegation worries by back-to-back victories.
In came Ben Foster, Darron Gibson and Anderson, while Nemanja Vidic made a welcome return to the defence for his first start of 2010. Rio Ferdinand, available after his four-match suspension, was conspicuous by his absence, leaving Wes Brown to partner the Serbian in the centre of defence.
A curious first half served up a cocktail of mistakes and brilliance. While the early sparring couldn't deliver a telling blow for either side, it did claim Anderson, who succumbed to a knee injury inside the first 15 minutes. Around the 20 minute mark, however, came a flurry of chances at either end.