The Baggies earned all three points at Old Trafford, with Chris Brunt's free-kick deflecting off Jonas Olsson and beating David De Gea, while Robin van Persie had a penalty saved
A combination of Chris Brunt and Jonas Olsson struck the decisive blow shortly after the hour at Old Trafford on Saturday, with the Albion skipper's 20-yard free-kick taking a wicked deflection off his team-mate to leave David de Gea helpless.
|VIEW FROM OLD TRAFFORD
|By Sam Lee
Well nobody quite expected that. The last time Manchester United were at Old Trafford they had beaten rivals City by four goals to two and everything seemed right with the world. This, though, is the third defeat on the bounce and Champions League football is not quite as assured as it had seemed, even as recently as midweek.
West Brom deserve eternal credit for a dogged, extremely disciplined performance which blunted United's attack, although the home side did not look too threatening in their own right anyway.
The Baggies are safe now but United face a testing final three fixtures as they look to hold off Liverpool, now just four points back, and claim a Champions League spot.
As was the case in their defeats at Chelsea and Everton over the last fortnight, Louis van Gaal's team could not make their domination of the ball count.
United were camped in West Brom's defensive third for much of the contest, but were simply unable to break Tony Pulis' stubborn visitors down and Brunt's fortunate effort condemned the hosts to a third loss in a row for the first time since 2001.
Van Gaal's side remain in the box seat to secure fourth spot and a place in the Champions League, but their poor form has left the door ajar for Liverpool, who now sit four points behind United after beating QPR.
The pattern of the game was set from the off, with United dominating the ball and West Brom defending deep, just as they did to foil Liverpool last weekend.
Van Persie tested Myhill with a scuffed shot, and the returning striker could have opened the scoring in the 19th minute when he flashed a first-time effort narrowly wide from Ashley Young's low cross.
United continued to probe but, with Van Persie understandably rusty after his lengthy lay-off and Wayne Rooney playing in a more withdrawn role, they struggled to carve out clear-cut chances against a typically well-drilled Pulis side.
The second half began in much the same vein as the first, with Rooney having United's first attempt on goal with a 25-yard pot-shot that Myhill gathered easily.
But it was West Brom - victors at Old Trafford last season - who broke the deadlock completely against the run of play, when Olsson unwittingly deflected Brunt's free-kick beyond De Gea.
United were gifted a golden opportunity to level shortly after, but Myhill made an excellent stop low to his left from Van Persie's penalty.
Myhill was in outstanding form, and was again on hand to deny Van Persie and substitute Angel di Maria in the closing stages to preserve his clean sheet, as United continue to stagger towards Champions League qualification.