Table-toppers Chelsea produced another classy performance but the only ingredient missing was a winning goal as battling Blues bravely maintained their impressive unbeaten run.
It was not a particularly happy game for Chelsea as, in the 89th minute, Florent Malouda was sent off for a second yellow card.
Dogged determination by Birmingham enabled them to collect another valuable point to maintain their creditable league position.
Once again Blues competed well against a top-four club and, on this occasion, they were often indebted to a superb display from their on-loan goalkeeper, Joe Hart.
Blues may still be looking for their first win over Chelsea in 29 years but they can be delighted with the point from a hectic goalless draw.
The match was a dream come true for avid Chelsea fan, Roger Johnson. The Blues defender came up against his hero, Didier Drogba, and emerged with a great deal of credit as he prevented the best striker in the world from scoring.
Chelsea, unbeaten in their previous 15 games against City, had numerous chances but, on this occasion, weak finishing and the goalkeeping skill of Hart prevented them from winning.
In the circumstances Chelsea boss, Carlo Ancelotti, who does not believe he needs to add to his squad in the transfer window next month, was often a placid, emotionless figure on the touchline as his side struggled to take control.
The story could have been entirely different if Cameron Jerome had scored in the opening minute following a solo run. This miss only appeared to spur Chelsea into a ten-minute spell of attacking pressure as they laid siege on Blues' goal.
Blues weathered this storm but Chelsea's star team were well in control with Drogba showing his potential danger. He produced one powerful shot on the volley which flew just wide as he began to find his range.
Shortly afterwards Blues were indebted to their young England goalkeeper, Hart, who dived low to his left to palm away a Danny Sturridge effort.
There was a controversial moment in the 27th minute when Frank Lampard ran through into an offside position. He gathered the ball and, with only Hart to beat, lofted his shot over the bar as if he was playing at Twickenham.
Blues were seemingly out of luck with linesmen's decisions as Christian Benitez tapped home from only a yard out from Liam Ridgewell's pass only to be ruled offside, while Sturridge fired just wide just before the break.
There was an anxious moment for Chelsea on the hour. Malouda was booked for a foul on Benitez and, after saving Seb Larsson's free-kick, Petr Cech smashed himself against a post and had to receive treatment.
With the encouragement of the Blues fans, Hart continued to thwart the Chelsea attack. Substitute Salomon Kalou had a wonderful opportunity but he jinked the wrong way and Hart was able to block his eventual shot.
In an attempt to break the stalemate Ancelotti took off Lampard and sent on Joe Cole to give the midfield a different dimension.
It was all to no avail although Drogba very nearly took advantage of a bad back-pass from Blues skipper, Stephen Carr. His late challenge caught Hart who had to receive extensive treatment for a head injury.
Malouda then received his marching orders for a foul on Carr to sum up Chelsea's afternoon.