Olivier Kapo struck twice for Brum and manager Steve Bruce said: "I'm glad to get that win because October is a bad month for me. I was sacked as manager of Huddersfield in October and there were people questioning whether I should stay this time last year.
"But that was a vital win. I said at half-time that if we are going to stay in the Premier League, we have to beat the teams around us. I expect Wigan to be one of those.
"We have now beaten Wigan, Derby and Bolton and were a minute away from beating Sunderland. It has got us up to 11 points and we've got an outstanding chance of staying in this division."
Bruce could not bear to watch the penalty from Kapo which brought City back on level terms for the first time before half-time.
"Once we'd got the penalty I'm thinking 'have I done the right thing?' but he stuck it away very well - apparently!
"It has always been a superstition of mine not to look at penalties. We don't get that many and when I have watched in the past we have usually missed."
Wigan manager Chris Hutchings admitted his side paid the penalty for some sloppy defending at the second equaliser from Birmingham skipper Liam Ridgewell and the winner from Kapo nine minutes from time.
He said: "We expect to do better at set plays like for the second goal. Then for the third Kapo has been allowed to turn on the edge of our box.
"At set pieces people have got jobs to do and we expect for them to carry them out. It has cost us.
"We are bitterly disappointed because we felt we deserved something out of the game.
"We are disappointed that we did not hold on longer on both occasions when we went in front but we have to take it on the chin and bounce back as quickly as possible."
Wigan striker Marcus Bent twice put his side in front only for Kapo (two) and Ridgewell to earn Birmingham a vital win after three successive league defeats."