Manchester United needed a controversial own goal from Birmingham defender Scott Dann to salvage a point from a 1-1 draw with Birmingham at St. Andrews as they missed out on the chance to replace Chelsea as Barclays Premier League leaders.
The Blues were incensed when referee Mark Clattenburg allowed the equaliser to stand after 63 minutes, cancelling out Cameron Jerome's first-half opener, and he consulted with one of his assistants before awarding the goal.
The Red Devils ended with 10 men after midfielder Darren Fletcher was sent off in the closing stages for a second bookable offence.
The draw enabled Blues to make club history in achieving their longest ever unbeaten top flight run of 12 games - a run stretching back to October.
Sir Alex Ferguson had demanded a response after the FA Cup reversal against Leeds and made seven changes to his starting line-up.
He could not have complained about the commitment and determination of his players and they completely dominated the opening 45 minutes and yet trailed to Birmingham's only shot on goal from Jerome.
But Birmingham showed the tenacity and fighting spirit which has been their trademark during an 11-game unbeaten run leading into this fixture.
And in the second half they posed more of a threat via the pacey Christian Benitez and United's Tomasz Kuszczak was the busier of the two keepers.
United dominated possession from the first whistle and City midfielder Barry Ferguson blocked a shot from Fletcher at the expense of a corner.
Birmingham were closing down in typical fashion but they were guilty of some poor distribution in the early stages.
Fletcher teed up Paul Scholes in space 20 yards out and it needed James McFadden to get in an important block at the expense of a corner.
Wayne Rooney got the better of Birmingham skipper Stephen Carr, who misjudged a pass down the line from Patrice Evra, and it needed McFadden to get in a vital block at the far post to keep out Luis Antonio Valencia's shot.
City keeper Joe Hart was tested for the first time after 24 minutes when he reacted quickly to block a shot from Rooney who had been found in space by Valencia.
It was one-way traffic towards the home goal and Rooney headed wide from a Fletcher centre.
McFadden brought down Scholes 25 yards out but Valencia's free-kick was charged down by Lee Bowyer.
Park Ji-Sung had an opportunity when running onto a Fletcher through-ball but he lost his balance when under pressure from Carr.
United appealed in vain for a penalty after claiming Carr had handled a pile-driver from Michael Carrick.
It was non-stop attacking from United and Dann threw his body in the way of another shot from Carrick.
But after 39 minutes Birmingham stunned United by taking the lead in their first worthwhile attack from Jerome.
The former Cardiff player forced a corner when his shot was blocked by Scholes.
United failed to deal with McFadden's centre, Bowyer headed the ball back across goal and it bounced off Johnny Evans to Jerome, who applied the finishing touch for his fifth goal of the campaign.
Birmingham then squandered a great chance to double their lead.
They found themselves in a two against one situation on the counter-attack but Benitez lost control and allowed Carrick to make a vital tackle when Jerome would have had a clear run on goal.
Fletcher became the first player to be yellow-carded after 44 minutes for a crude challenge on Bowyer.
Benitez found himself in a promising position in the United box at the start of the second half but was dispossessed by Wes Brown.
But the Ecuador international forced a low save out of Kuszczak after United had failed to fully clear a Sebastian Larsson corner.
United finally drew level after 63 minutes through an own goal from Dann.
The central defender was under pressure from Park when he turned a low centre from Evra past Hart.
Park was immediately substituted and replaced by Ryan Giggs.
Birmingham tried to retaliate and Benitez turned away from Evans and had a fierce shot beaten out by Kuszczak.
Carr, who has just returned from suspension, collected his sixth booking of the season for bringing down Evra but Rooney's free-kick was deflected wide.
Larsson was booked for dissent after feeling he should have been awarded a free-kick following a challenge by Evra.
Hart held onto a low Valencia drive and Scholes fired over the bar as United searched for the winner.
But their hopes were ended when Fletcher was sent off for a second bookable offence after 84 minutes for a foul on Jerome.
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