It had to happen on Groundhog Day. City have been condemned all season to suffer in the west midlands, and while they avoided the defeats handed out by West Brom, Wolves and Aston Villa, they succumbed once more to the jinx.
Even though Ben Foster in Birmingham's goal hardly had a save to make, the Blues should have left St Andrews with the victory they badly needed to maintain their impetus in the chase for Champions League football.
While Roberto Mancini counted his wounded - Micah Richards and Nigel de Jong with head injuries, Joe Hart with a split eyelid on the ground where he was a loan-star hero last season - he also mourned the loss of two points.
Craig Gardner's penalty denied the Blues the precious 2-1 win that would have taken Mancini's men within a point of second-placed Arsenal and, perhaps more importantly, four points ahead of resurgent Chelsea.
City knew that they had to get a positive result after the midweek victories enjoyed by their top-four rivals, and a combination of enterprise, good passing and a trace of luck engineered the vital early goal.
Carlos Tevez set the move in motion, finding David Silva with one touch to allow the Spanish star to do what he loves most, running at defenders and reaching the penalty area, before he entrusted the ball with Tevez again.
City's skipper manoeuvred himself into a shooting position and, although his shot lacked the venom he would have preferred, the deflection off an attempted block helped the ball bobble inside Foster's far post.
Birmingham knew they had a game on their hands, but the Blues somehow managed to squander their advantage as the game unfolded. They were fortunate to get away with a Gareth Barry clearance that lined up a volley for Nikola Zigic.
But when David Bentley flirted in a 23rd-minute free kick that was allowed to skip and bounce, Zigic claimed what could only have been the merest of touches but it was enough to help the ball past stranded goalkeeper Hart.
As soft goals go, it was somewhere between marshmallow and candy floss. Tasty enough when you are the team benefiting but horrendous to concede, and already it was looking like being one of those nights.
That feeling took further root when Richards launched himself into a mighty clearance only for his momentum to carry the defender into a clash of heads with team-mate De Jong, pole-axing the pair of them.
Tough-nut Dutchman De Jong staggered off to get stitches and returned wearing the biggest bandage in the doc's bag, but after several minutes of treatment on the pitch, Richards was stretchered off to hospital
Kolo Toure came on for the unfortunate Richards, so City's rearguard was hardly diminished, and it was a defender in the shape of left-back Aleks Kolarov who regained the lead for the Blues after 40 minutes.
Edin Dzeko won the free kick on the edge of the area then Barry and Silva played their parts in disrupting the Birmingham wall as Kolarov curled the ball around and inside the far post, his second goal in four games.
Kolarov went into the book soon after for his trip on Bentley - he joined De Jong, who had committed the same offence earlier - but City nevertheless enjoyed their half-time breather in the ascendency.
Jerome Boateng might have made it a collector's item of a City performance - when did both full-backs last score in the same match? - but directed his Dzeko-created second-half chance straight at goalkeeper Foster.
Stephen Carr might have offered Tevez the chance to end his mini-slump of two successive missed penalties with what appeared to be a deliberate hand-ball to block James Milner's cross, but the officials were unmoved.
Referee Friend was more receptive to Birmingham appeals in the 77th minute when half-time substitute Patrick Vieira ran into Kevin Phillips in the box, and Gardner fired the home side level from the spot.
It was a goal that gave Birmingham greater heart for the finale, and City had to survive one or two hairy moments to hang on to the point, even if Kolarov almost scored with a repeat of his free kick in the dying seconds.