Manchester United cruised past lifeless West Brom to cement themselves as the second-placed team in the Premiership.
Paul Scholes set the ball rolling with a strike from the edge of the box after a good run from Rio Ferdinand.
Ferdinand turned scorer in first-half injury time when he planted a firm header in from Ryan Giggs' corner.
The victory was completed when Ruud van Nistelrooy headed home a cross from substitute Alan Smith midway through the second half.
It only took a few minutes for the game to take the pattern many would have anticipated.
The Baggies hardly got into the United half and appeared content with containment - a plan that certainly worked in the first 30 minutes if the summit of their ambitions was a goalless draw.
Paul Robinson kept Wayne Rooney on a tight leash and, although Scholes went close with a close-range header that should have given them the lead, the home side were unable to break through.
But the game opened up on the half-hour in unexpected circumstances when Robinson received a head injury after clashing with a team-mate while trying to clear a corner.
A long stoppage followed and, with Robinson hardly down the tunnel on the stretcher, the home side took the lead.
Ferdinand made a quick break down the right flank and Ji-Sung Park was able to lay the ball back to Scholes on the edge of the box and his left-foot effort beat Tomasz Kuszczak and flew into the corner.
Robinson's injury had proved costly and was to do so again as United doubled their lead in injury time.
Giggs swung over a corner from the right and Ferdinand rose well on the penalty spot to plant a powerful header into the West Brom goal.
There seemed little prospect of a Baggies recovery and United were comfortable throughout the second half.
The third goal inevitably arrived midway through the second period as Park released Smith down the right.
The former Leeds man, knowing exactly what sort of service a centre-forward needs if they are to thrive, hit a teasing cross that Van Nistelrooy met with a header, giving Kuszczak no chance.
From then on, it was just a case of the visitors waiting for the final whistle without a decent memory to take with them back down the motorway.
It was their ninth away game without a Premiership victory and a similar approach to other games would not see much of an improvement to their fortunes.
Man Utd boss Alex Ferguson:
"It was a convincing performance, even if we took a bit of time to get going.
"We just have to keep going. The important thing is to win and if we keep going then you never know.
"I think confidence is a big factor with the team because we are starting to play well."
West Brom boss Bryan Robson:
"It was disappointing to switch off for the first and conceding just before half-time was a big blow.
"But we have got games against Tottenham and Aston Villa coming up and our home form has been pretty good."
Man Utd: Van der Sar, Neville, Ferdinand, Brown (Richardson 45), O'Shea, Park, Fletcher, Scholes (Smith 61), Giggs, Rooney, van Nistelrooy (Saha 66).
Subs Not Used: Howard, Bardsley.
Goals: Scholes 35, Ferdinand 45, van Nistelrooy 63.
West Brom: Kuszczak, Albrechtsen, Curtis Davies, Gaardsoe (Gera 67), Robinson (Kamara 32), Watson, Chaplow, Wallwork, Carter, Greening, Ellington (Campbell 61).
Subs Not Used: Horsfield, Kirkland.
Ref: M Clattenburg (Co Durham).