Eurosport - Sat, 20 Feb 17:00:00 2010
Fulham had trailed through a bizarre third-minute own-goal by right-back Chris Baird and, while they dominated possession for large parts of the game, chances were even between teams with contrasting styles but similar levels of effectiveness.
Damien Duff levelled with a splendid effort on the hour mark and - after James McFadden saw a shot hit the crossbar and bounce off the line - Zamora struck with a left-foot free-kick to seal the win that England boss Fabio Capello ironically missed, having already left Craven Cottage.
They could have doubled their advantage five minutes later, Keith Fahey's goal-bound finish blocked by Baird after hesitant defending from Brede Hangeland.
It was a shock start for Fulham, who soon regained some composure and controlled possession with their typical short passing game on a worn-looking pitch.
Visiting keeper Joe Hart was barely tested, though well protected by a stingy defence that largely restricted Fulham from creating too many meaningful chances.
Simon Davies's volley from Baird's pass forced a smart stop from Hart, while a falling Davies looped a header into the England hopeful's arms, his only real work of the half.
Hangeland headed one corner over, Zoltan Gera had a half-hearted penalty appeal turned down when he was muscled away from a loose ball in the box by Stephen Carr, and Zamora put Gera's cross wide at the far post after a slick move.
The second half saw more of the same, as Fulham moved the ball well while Birmingham showed their gritty resolve and work-rate to compete for every ball.
Zamora almost repeated his spectacular volleyed winner against Shakhtar Donetsk but this time Hart was well-placed to save, and Birmingham went down the other end only for Cameron Jerome to fire a weak finish straight at Schwarzer.
Fulham levelled on the hour thanks to a fantastic strike from Duff.
The Irishman cut inside from the right, played a one-two with Gera and, after drifting across the penalty area, fired a cracking left-foot drive in off the post, leaving Hart with no chance.
Birmingham showed great determination to rally after conceding, and bossed the subsequent 15 minutes, employing a direct approach and almost taking the lead again through a moment of magic from McFadden.
The Scotland forward hammered a vicious drive that took the faintest of touches off the flailing Schwarzer, rattled the crossbar and bounced on the line and away.
The Blues were buoyant as Fulham launched a rearguard action to stave off their aerial assault, but Zamora - who put in a typical bustling performance in front of Capello - had his say.
With a minute left on the clock, Carr clattered into Gera right on the edge of the box and Zamora, for whom skipper Danny Murphy stepped aside, angled a left-foot drive around the wall and into the top left, via the palm of Hart.
It was a superb strike, taking his overall tally to 15 for the season with eight in the league, and one that makes Fulham unbeaten in six matches.
Roy Hodgson's side climb above Birmingham on goal difference, one point behind Everton in eighth although both the Toffees and the Blues have a game in hand.