Leeds United set up an FA Cup tie at home against Tottenham after coming from behind to beat Birmingham 2-1 in their third-round replay.
Wade Elliott put Birmingham ahead shortly after the half-hour mark, just as he had done in the initial meeting which finished 1-1 10 days ago.
But once again Leeds levelled after the break, this time courtesy of Ross McCormack's first goal since September - an effort which had not looked like coming with 19-goal striker Luciano Becchio, a reported January transfer target for a handful of clubs, missing due to illness.
El-Hadji Diouf, celebrating his 32nd birthday, then quickly completed the turnaround, keeping his cool to chip home from the penalty spot after Paul Robinson had been penalised for handball.
It means Leeds will now host Spurs in the fourth round of the competition in a televised clash next Sunday, denying cash-strapped Birmingham the chance to pick up a welcome sum in the region of £200,000.
United's first win at St Andrew's since 1996 also provided them with their 100th in FA Cup history and sealed progress from the third round for only the second time in 10 years.