Clint Dempsey salvaged a point for Fulham and denied Birmingham a first Premier League away win since March.
With 20 minutes gone, Alexander Hleb capped a marauding run through the Fulham defence with a well-timed ball to Sebastian Larsson, who swept home.
Fulham left the field at half-time to a chorus of boos, but striker Dempsey nodded them level just after the break from Zoltan Gera's looping header.
Scott Dann later shuddered the bar for the visitors.
Given that Birmingham have not won on their travels for eight months, while Fulham are without a victory of any kind since late October, it was hardly the most unpredictable of results.
Yet neither the background to the contest, nor the fact that this was Fulham's ninth league draw of the season and Birmingham's eighth, could disguise the fact that the comeback at one stage seemed beyond the home side.
Fulham character pleases Hughes
At half-time, having watched his side outclass the Cottagers for 45 minutes, Birmingham manager Alex McLeish could have been forgiven for anticipating a rare away victory to mark his third anniversary in charge.
He might even have contemplated raising a glass to Hleb, who offered spectacular evidence of his Arsenal and Barcelona pedigree in the build-up to the visitors' opener.
Racing along the inside left channel, the Belarus international, on a season-long loan from the Nou Camp, drove into the box before wrong-footing the backpedalling Carlos Salcido to find Larsson with a slide-rule pass.
The Sweden international made no mistake, his low shot following an unerring course across Ben Foster and into the far corner.
Salcido was replaced by John Paintsil not long afterwards, but Fulham's problems ranged beyond the right-back position.
Deprived of the services of a trio of injured strikers after Andrew Johnson joined Bobby Zamora and Moussa Dembele on the sidelines, the hosts rarely troubled the Birmingham rearguard in the first half.
Larsson had been obliged to clear an early Aaron Hughes effort off the line, but Fulham were otherwise poor and the home support made their displeasure plain at the break, greeting referee Howard Webb's whistle with a chorus of derision.
Clearly the message hit home, for Fulham emerged with a new sense of urgency and purpose, and were rewarded with an equaliser inside seven minutes. Gera nodded a Simon Davies corner back across goal, and Dempsey was on hand to head home at the near post.
McLeish disputes corner leading to Fulham goal
It was a rare moment of incisiveness from Fulham, who squandered a host of set-piece opportunities, but it was sufficient to reignite the belief of both supporters and players.
Yet for all Fulham's second-half pressure - Kamara had an effort superbly blocked by Dann, one of several occasions on which he was thwarted by Birmingham's back four, while substitute Eddie Johnson brushed the side netting - it was the visitors who came closest to breaking the deadlock.
Larsson was once again in the thick of things, swinging a corner into the danger area from where Dann, eluding his marker, sent a powerful header crashing against the bar.
It was one of few promising second-half moments for Birmingham, but not even the departure of Hleb, who was carried off on a stretcher after succumbing to a hamstring problem, could lift Fulham sufficiently to draw a line under what is now a five-game winless streak.
This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.