The Eagles fans have not forgotten Bruce for walking out on Crystal Palace six years ago but the crowd were silenced by Cameron Jerome's first-half goal that gave Birmingham their ninth away win of the season.
The Blues were good value for their first-half lead and it was surprising it didn't come earlier as they had to wait 34 minutes before Jerome tucked away his seventh goal of the season.
Indeed Nicklas Bendtner should have opened the scoring after only two minutes after a great solo run from Fabrice Muamba followed by a neat pass from Jerome saw the on-loan Arsenal man in front of goal, but he shot well over.
Palace then had a couple of narrow escapes as shots from Stephen Clemence and Jerome were desperately deflected away from danger.
But Palace could hold out no longer as good work from Bendtner and Gary McSheffrey left Jerome ten yards out but, with his back to goal, he turned quickly to place a low right-foot shot past Gabor Kiraly.
Although Palace had lots of good possession they lacked the guile to open up the Birmingham defence. Colin Doyle in the City goal was still looking for his first shot to save but nonetheless was grateful when Paul Ifill's low effort hit the foot of the post and span away to safety.
After the break it was a bit of a stroll for Birmingham. Palace gave the ball away far too cheaply and Doyle was asked to make only one save from James Scowcroft ten minutes from the end.
Birmingham skipper Damien Johnson controlled the midfield and, with Clemence, gave Palace little scope to move the ball around. Ifill was left to do far too much on his own as the Eagles depended on him to penetrate the Blues defence.
But the Palace wideman, so impressive in the first half, was watched carefully and little stemmed from him when Palace needed him in the final 30 minutes.
Ironically, Kiraly didn't have a shot to save all game but, in the dying minutes, could have been embarrassed when a snap 40-yard volley from McSheffrey sailed narrowly over the bar with the Hungarian keeper stranded well off his line.