In a twist of fate that could have a significant effect on the title race, the master of Old Trafford found himself surprisingly cast in the role of victim.
Leading through Dimitar Berbatov's beautifully-finished second-half goal and with the clock ticking down, Ferguson must have been thinking about a job well done at a difficult hunting ground for the game's top four.
Giving United the Blues: Lee Bowyer scores Birmingham's equaliser
But thanks to a well-directed cross, adisputed handball and the goal-sniffing ability of Lee Bowyer,Birmingham manager Alex McLeish inflicted upon his former mentor what many would see as a delicious irony.
A draw would have been enough to taketop spot from Manchester City on goal difference but it seemed that Berbatov's strike had put United out on their own. Again.
Birmingham, with their own problems after dropping into the bottom three for only the second time this season, threw caution to the wind, however.
Substitute Nikola Zigic launched himself at Roger Johnson's centre and when the ball came off his arm andfell into the path of Bowyer, he slipped the ball under Edwin van der Sar. The Dutch goalkeeper booted the ball in the direction of the assistant referee but the officials would not be moved.
It would be nice to report that the visitors accepted their stroke of misfortune with good grace. ButFerguson moaned that the referee missed a foul on Nemanja Vidic along with Zigic's handball.
Eye for goal: Dimitar Berbatov fires home for United
'It hit his arm,' admitted McLeish. 'But there was a melee, it wasn't as if he did it deliberately. It definitely wasn't offside.'
That was a far more accurate summation than the castigation referee Lee Mason suffered from Manchester United's irate boss after the final whistle.
But when Manchester City are proving to be more than noisy neighbours and with a race that is there to be won'by six or seven teams', according to Ferguson, charity was clearly in short supply.
United's boss was more accurate in the brief condemnation of his own team for failing to 'kill off' Birmingham. Twice they hit the woodwork.
At the centre of it all was Berbatov.For so long, he has failed to rise to the challenge of being the main man. At the moment, he is clearly relishing the challenge.
Ever since he arrived from White HartLane in a £30million move it has appeared as though the Bulgarian either resented or was unable to cope with living in Wayne Rooney's shadow.
Pure delight: Berbatov celebrates his goal at St Andrew's
But with the erstwhile golden boy's star on the wane following his lapse in form and the rumpus over his contract, Berbatov has seen his chance.
At St Andrew's, he took a tighter grip on the crown. A game of few chances really was in the balance when Berbatov's backheel set Darron Gibson off down the right. The Bulgarian didn't admire his work but quickly made tracks towards Ben Foster's goaland controlled a return pass before planting alow, right-foot shot inside the post.
It was his eighth goal in three starts and took his tally for the season to 15. When he arrived it seemed that he was not able to live in Rooney's shadow. Now, it seems the roles are reversed. Out of the darkness and into the light, indeed.
Two minutes after the goal, he scaredBirmingham once more but this time his low drive hit the post.
Foster had pulled off a fine fingertip save in the pick of the chances in the first-half when Ryan Giggs, deployed on the right, had clipped a ball to the far post, where Birmingham's keeper touched it on to the upright.
Having a go: Birmingham's Sebastian Larsson has a shot on goal
Craig Gardner had gone close with a couple of efforts but McLeish had a couple of trump cards on the substitutes' bench. When all else fails, it is handy for the Scot to be able to call upon Zigic, all6ft 8in of him, if for nothing else but nuisance value.
With Kevin Phillips also in attendance, McLeish has a man able to find the net in a second if necessary. But it was Bowyer who latched onto the loose ball.
'A defeat would have been a bit toughon us,' said McLeish. 'It was just one moment of magic from Berbatov that looked to have settled it. It was a great finish.
'What I can do, though, with this group of players is make changes. It did look like it came off his arm.
'But, do you know what? Ultimately, Idon't care.'
There were at least five other managers in the Barclays Premier League who shared exactly thosethoughts come the final whistle.
Birmingham 1 Manchester United 1 - All the action as it happened Birmingham keeper Foster has no regrets over leaving 'cut throat' UnitedMANCHESTER UNITED FC