Paul Scholes made it three goals in two league games as Manchester United cruised past West Brom.
The hosts began confidently but were rocked by first-half injuries to Darren Moore and Cosmin Contra, forcing Bryan Robson into a double change.
United broke through on 53 minutes when Scholes latched onto Ryan Giggs' back-heel and lashed home a fierce shot.
Ruud van Nistelrooy's close-range header made it 2-0, before Scholes nodded in a third.
It was a harsh scoreline for battling West Brom, who were watched by a record crowd since The Hawthorns became an all-seater stadium of 27,700.
The hosts made a bright start against their somewhat subdued opponents.
Rob Earnshaw, back in the starting line-up after four goals in three games, sent an early effort wide before Zoltan Gera found a way through the United defence but shot too close to Roy Carroll.
United responded through Wayne Rooney, whose swerving shot skimmed past Russell Hoult's left-hand post.
And just as United began to find their stride, Albion's rhythm was upset when Moore failed to run off a leg injury and was replaced by Thomas Gaardsoe midway through the half.
Scholes took advantage of the resulting hesitancy in the home defence, finding space before firing a right-foot shot across goal.
Two minutes later, Robson, who had been hoping to frustrate former manager Sir Alex Ferguson, was forced into a second substitution.
Contra, who had looked threatening down the right wing, limped off to be replaced by Paul Robinson.
And the chances kept coming for United.
Rooney headed over Van Nistelrooy's clever lofted cross and Giggs smashed a free-kick just outside the area straight into the wall.
The half-time whistle provided a welcome respite for the hosts - but United continued where they left off after the break and made a deserved breakthrough on 53 minutes.
Giggs found Scholes charging through the middle and the midfielder celebrated his only his second goal of the season.
West Brom worked hard in defence but could not muster an attempt on goal, and it was no surprise when United struck again.
Gabriel Heinze headed Giggs' free-kick across goal where an unmarked van Nistelrooy headed in his first Premiership goal from open play this season.
Scholes, who had not scored in the Premiership before last Saturday's goal against Charlton, wrapped up a routine win eight minutes from time.
West Brom failed to clear a Giggs free-kick and Rooney eventually headed across for Scholes to nod home a simple goal - and send West Brom to the bottom of the Premiership.
West Brom: Hoult, Scimeca, Moore (Gaardsoe 24), Purse, Clement,
Greening, Sakiri (Horsfield 75), Johnson, Gera,
Contra (Robinson 38), Earnshaw.
Subs Not Used: Kuszczak, Hulse.
Man Utd: Carroll, Brown, Ferdinand, Silvestre, Heinze,
Fletcher (Ronaldo 72), Keane, Scholes, Giggs,
van Nistelrooy (Smith 75), Rooney.
Subs Not Used: Howard, O'Shea, Fortune.
Goals: Scholes 53, van Nistelrooy 72, Scholes 82.
Ref: S Bennett (Kent).