Nikola Zigic scored four goals, including a seven-minute hat-trick, as Birmingham thrashed Leeds at Elland Road to maintain their promotion push.
Ross McCormack put Leeds ahead with a low effort before Zigic headed home Wade Elliot's cross to equalise.
The striker fired his side into the lead after 61 minutes and added to it with headers in the 64th and 68th to extend their unbeaten run to 10 games.
Birmingham are now up to fourth in the Championship, while Leeds sit 10th.
Much of the home crowd turned on Leeds chairman Ken Bates after Zigic's fourth.