Former Birmingham co-owner David Sullivan was denied victory on his return to St Andrew's as his current club West Ham were pegged back in a 2-2 draw.
The bottom-placed Hammers looked set for a first away success of the campaign after Frederic Piquionne and Valon Behrami had put them in command.
But Cameron Jerome and Liam Ridgewell salvaged a point for Alex McLeish's side.
West Ham started well and it needed a brilliant save from Ben Foster to deny Carlton Cole the opening goal after 17 minutes.
In a rare Birmingham attack, Alexander Hleb picked out the run of Keith Fahey but he was crowded out as he prepared to shoot.
West Ham needed only three minutes of the second half to break the deadlock through Piquionne's fourth of the campaign. Luis Boa Morte picked out the run of Piquionne between Ridgewell and Roger Johnson and he drilled his shot across Foster into the far corner.
Cole came close to making it 2-0 when his glancing header was only just too high from Victor Obinna's corner, and it was no surprise that Behrami doubled the Hammers lead after 57 minutes. Cole had time to pick out Behrami and his first-time shot flew past Foster from 12 yards.
City manager McLeish responded by bringing on Jean Beausejour and Craig Gardner in place of Hleb and Fahey, but it was almost 3-0 when the woodwork denied Boa Morte.
Jerome gave Birmingham a lifeline by reducing the arrears after 63 minutes. Nikola Zigic headed a cross from Sebastian Larsson into his path and the former England Under-21 striker made no mistake from close range.
And Ridgewell snatched a point on 73 minutes when England goalkeeper Rob Green only succeeded in pushing a free-kick from Larsson straight into the path of the defender, who made no mistake from eight yards out.