Manchester United piled the pressure on Premiership leaders Arsenal and plunged West Brom to rock-bottom at The Hawthorns.

The gulf in class was painfully evident to Gary Megson's battlers from the moment Ruud van Nistelrooy cancelled out Jason Koumas' stunning seventh-minute opener.

Paul Scholes and Ole Gunnar Solskjaer took advantage of suicidal Albion defending to take Sir Alex Ferguson's men to within two points of the Gunners - and allow West Ham to leapfrog the beleaguered Baggies at the other end of the table.

United were shorn of the rested Ryan Giggs but with Roy Keane back in the middle and Scholes moving up to form a three-pronged strike-force alongside van Nistelrooy and Solskjaer, the last thing the visitors needed were defensive hand-outs.

But Albion lapsed within 30 seconds of Koumas' opener and from then on it was plain sailing for the Old Trafford title chasers.

Russell Hoult made his first vital save in the fifth minute after Keane's lofted through-ball had sent Solskjaer clean through.

But Albion grabbed their seventh minute lead out of nothing when Koumas - by far the Baggies' most creative influence - latched onto a misplaced pass from Rio Ferdinand and bore down on the United goal before unleashing a right-foot shot which beat Barthez on his right-hand post.

Just as it had after Daniele Dichio's early goal against Arsenal, the Hawthorns erupted - but, as against the Gunners, Albion could not hold their lead for long.

Straight from the restart David Beckham punished a Neil Clement mistake by playing the ball over the top for an unmarked van Nistelrooy to poke the equaliser through Hoult's legs from six yards.

Darren Moore headed clear from Solskjaer as United sought to build on the Dutchman's equaliser and the Albion defence did not help themselves by affording the visiting strikeforce far too much space in the final third.

Albion became increasingly reliant on Koumas-influenced counter-attacks with Andy Johnson and in-form Daniele Dichio both blazing half-chances well wide.

Scholes settled any remaining United nerves for the time being when he struggled free of his would-be marker Larus Sigurdsson and swept home Keane's tight cross from close range in the 22nd minute.

Keane's majesty in the middle was evident in the superb 40-yard ball with which he found Solskjaer in the 28th minute but Hoult proved equal to his final shot.

Sigurdsson might have made up for his earlier error in the 38th minute when he headed Koumas' left-wing cross well wide at the far post after a brief and rare period of Albion pressure.

Former United man Ronnie Wallwork fired well wide but it was United who ended the half by coming closest when Moore headed clear from under his own bar to deny the lurking van Nistelrooy.

Scholes flashed a low shot just wide of Hoult's left-hand post as United tried to make the game safe at the start of the second half.

Albion went on to enjoy arguably their best spell of the game but they failed to make a breakthrough and were inevitably punished for it.

A rare hiccup between Ferdinand and Neville in the United defence gave Daniele Dichio a half-chance from Roberts' cross into the United box but Neville recovered to force the Albion front man to concede a goal-kick.

Then Ferdinand made a hash of Ronnie Wallwork's harmless ball into the United box - but if Albion thought they had stumbled across a chink in United's armoury they were sadly mistaken.

The visitors swept upfield and after Gary Neville's deep cross from the right had eluded everybody in the Albion box Solskjaer swung in at the far post and sent United's third into the top corner of the net.

Solskjaer ought to have grabbed his second five minutes later after Koumas lost possession in the United half and Beckham found his team-mate with an audacious 40-yard crossfield ball.

But this time Solskjaer attempted to loft his shot over the advancing Hoult and the ball sailed just wide of the left-hand post.

Koumas' precise ball from the left in the 66th minute might have found Dichio stealing into the box but Ferdinand intercepted confidently to clear the danger.

Keane's saving tackle then prevented Dichio stealing in on the end of Roberts' right-wing cross and Koumas wasted a couple of dangerous-looking free-kicks of the type he had netted so confidently against Sunderland.

Teams

West Brom: Hoult, Moore, Gilchrist, Sigurdsson (Dobie 75), Adam Chambers (Balis 86), Koumas, Johnson, Wallwork, Clement, Dichio, Roberts.

Subs Not Used: Murphy, McInnes, James Chambers.

Goals: Koumas 6.

Man Utd: Barthez, Gary Neville, Ferdinand, Brown, Silvestre, Phil Neville, Beckham, Keane (O'Shea 81), Scholes, van Nistelrooy, Solskjaer (Forlan 67).

Subs Not Used: Blanc, Ricardo, Richardson.

Booked: Scholes.

Goals: van Nistelrooy 8, Scholes 23, Solskjaer 55.

Att: 27,129

Ref: N Barry (N Lincolnshire).