Marlon King’s sensational 90th minute winner settled a dramatic encounter against ten-men Burnley at Turf Moor.
Blues surged ahead thanks to Curtis Davies’ 21st minute opener, but the Clarets struck back early in the second-half through Ross Wallace’s penalty.
The game turned on its head when Dean Marney saw red just after the hour mark – and King displayed his predatory instincts with a brilliant volley to secure a vital 2-1 win.
Burnley created the better opportunities in the opening stages, with Sean Dyche’s men knocking the ball around confidently.
The first chance arrived on six minutes when Wallace cut in from the right by-line and stood the ball up for Danny Ings, who headed inches wide of Jack Butland’s left post.
The two combined again ten minutes later as another Ings header drifted just over from the tricky Wallace’s cross.
Davies made the hosts pay for their inaccuracy in front of goal, however, as his stooped header from Rob Hall’s corner nestled in the bottom corner.
The visitors were in complete control for the remainder of the half; dealing with any Burnley forays into their box. The Clarets could only muster shots via Chris McCann and Dean Marney, which Butland held at ease.
Lee Clark’s side played with real maturity during the first 45 minutes and deserved their lead.
But Burnley soon drew level after the break. If it wasn’t for Sam Vokes smacking the upright from just a few yards out and Butland producing a world class save from Wallace’s flick on, then things could have been even worse.
Birmingham couldn’t keep the Turf Moore outfit at bay forever, though, as Wallace equalised from the penalty spot, after the assistant referee deemed that Paul Robinson fouled Junior Stanislas inside the area.
Davies could have quickly restored his team’s advantage but the centre-back could only head Wade Elliott’s corner straight at Lee Grant.
Rather than the game settling down, the referee sent off Burnley’s Marney for what he saw as an illegal tackle on Robinson.
The contest was wide open from that point onwards but constant Blues pressure paid off after an almighty effort.
King had claims of a handball in the penalty waved away, then on 85 minutes Nikola Zigic headed Burke’s cross onto the post from point-blank range.
But Birmingham were not to be denied as King spectacularly volleyed home his 14th goal of the season, after Zigic flicked Elliott’s angled delivery into the area.
Burnley: Lee Grant, Daniel Lafferty, Jason Shackell (C), David Edgar, Kieran Trippier, Junior Stanislas (Martin Paterson 83), Dean Marney, Danny Ings (Keith Treacy 90+1, Ross Wallace (Brian Stock 78), Chris McCann, Sam Vokes.
Subs not used: Brian Jensen, Dean Richards, Luke O’Neill, Keith Tracey, Kevin Long.
Goals: Wallace (pen, 55)
Sent off: Marney (61)
Blues: Jack Butland, Paul Caddis, Steven Caldwell (C), Curtis Davies, Paul Robinson, Chris Burke, Morgaro Gomis, Callum Reilly (Nikola Zigic 69), Wade Elliott, Rob Hall (Nathan Redmond 54), Marlon King.
Subs not used: Colin Doyle, Mitch Hancox, Hayden Mullins, Ravel Morrison, Peter Lovenkrands.
Goals: Davies (21), King (90)
Referee: D. Drysdale
Attendance: 11, 576 (418 Blues fans)