Craig Gardner netted a late equaliser as to snatch all three points away from Spurs in a 1-1 draw at St Andrews.
Peter Crouch brought a decent save out goalkeeper Ben Forster and Scott Dann then produced a smart block to deny Jermain Defoe as Spurs started brightly.
And they took a deserved lead on 19 minutes when a punched clearance fell to Sebastien Bassong and he made no mistake by blasting the ball high into the net.
Birmingham rarely threatened in the opening 45 minutes and the best chance they could muster saw Heurelho Gomes comfortably deal with a Gardner shot.
But they started the second half well and Gomes was forced to punch away a Gardner free-kick before making a good reaction stop to deny Birmingham’s top scorer.
Gardner was proving to be a thorn in Tottenham’s side, playing in Cameron Jerome only for William Gallas to make a timely block.
But Blues would clinch a point when Dann launched the ball into the box and Nikola Zigic teed up Gardner to find the net