Manchester United 2 Birmingham City 0
The game marked a return to Old Trafford for former United hero Steve Bruce, but goals from Diego Forlan and David Beckham ensured he left empty-handed.
United dominated proceedings from the start but were forced to wait until near half time before making their superiority count.
Forlan netted his eighth goal of the season in the 38th minute to round-off a fine move by United.
Birmingham came out on the attack in the second half and former United youngster
Jovan Kirovski almost drew the visitors level on 55 minutes but Fabien Barthez produced a good reaction save to keep the forward's header out.
Barthez was again called into action soon after to keep United ahead when he brilliantly saved Aliou Cisse's point-blank header.
United then started to assert the dominance on the encounter and wrapped up the points with a fine finish from the recalled Beckham.
Juan Sebastian Veron sent Beckham clear on goal with a superb pass and the England captain produced a delicate chip to beat Nico Vaesen in the visitors goal.