Two polar opposite halves were on show at Bloomfield Road today, as Blackpool's afternoon turned sour after a catastrophic second period.
All seemed to be going to plan at the break, as Andy Keogh's smart finish had The Seasiders on course for victory.
However when Lee Novak fired the visitors level the game changed. Jack Robinson scythed down Jordan Ibe as Pool were reduced to ten men, which would prove costly.
Home misery was complete when that man Novak nicked Birmingham the points with a glancing header from close range, just eight minutes from time.
Barry Ferguson had named an unchanged side for the third week running.
However after just two minutes Birmingham's Federico Macheda should have given his side the lead, missing his kick whilst attempting to latch onto Novak's cross.
The Manchester United loanee was clearly keen to make his mark, heading over soon after.
It was certainly a lively start, Keogh set up Faris Haroun for The Seasiders, but he could only lash over wildly.
The Belgian returned the favour soon after, running onto David Perkin's through ball, but his cross couldn't be turned home by Keogh.
Kirk Broadfoot then had a header tipped over, but it was only a matter of time before the hosts took the lead.
The breakthrough duly arrived from a corner on 22 minutes, when Keogh swivelled on the spot, before smashing home the opener for his second goal in successive home matches.
In a rowsing atmosphere Pool were in their element, Stephen Dobbie was next to try his luck, being denied by Darren Randolph.
But as the half went on the chances lessened, as Blackpool went in for half-time ahead for the first time since early December
Half Time: Blackpool 1 Birmingham 0
The visitors came out for the second half revitalised, and Chris Bruke tested Matt Gilks moments after play restarted.
And they should have levelled ten minutes later, a quick counter attack was spearhead by Nikola Nigic baring down on goal, but his attempted chip fell comfortably into Gilks' hands.
Just before the hour mark Ferguson reacted, bringing on Elliot Grandin and Ricardo Fuller for Angel Martinez and Steve Davies.
And the Jamaican was instantly involved, breaking down the right, before stinging the palms of Randolph, with Haroun firing the rebound straight at the goalkeeper.
However from the next attack City levelled, Chris Burke's cross was headed down by Zigic into the path of Novak, who lashed home the equaliser from the edge of the box.
That sprung the visitors into life, and they could have had a penalty as Burke went down in the area, before Andy Halliday replaced Dobbie for Blackpool.
With 15 minutes remaining the game took a further twist, as substitute Ibe broke clear and was taken out by Robinson.
The referee took his time before brandishing the red card, the left-back's third of the season.
Ibe was now becoming a menace, next he cut in onto his left foot, before shooting at Gilks.
And that dismissal proved costly eight minutes from time when Birmingham completed the turnaround. It was Novak again who glanced home Emyr Huws' cross to make it 2-1.
The visitors were now rampant, next Macheda's shot had to be turned around the post by Gilks.
After the board for added time went up there was still one chance left for Blackpool, but Haroun shot wide from Gary MacKenzie's knock down.
Full Time: Blackpool 1 Birmingham 2
By Mark Ridgway