Birmingham remain deep in relegation trouble after losing their final Premier League home game of the season 2-0 to Fulham.
The Blues started nervously with keeper Ben Foster almost beaten by a long kick from opposite number Mark Schwarzer.
Foster clawed the ball away but from the resulting corner Brede Hangeland powered in a downward header.
And the defender volleyed in a second after the break as Fulham recorded just their third away win of the season.
The result leaves Birmingham, who have won only two of their last 11 league games since their League Cup triumph in February, level on points with Blackpool and Wigan but out of the relegation zone on goal difference, by just one goal.
The Blues go to Tottenham on the last day of the season knowing a win will be enough to keep them up if Blackpool fail to win at Premier League champions Manchester United or Wigan do likewise at Stoke.
Boss Alex McLeish would have hoped to guarantee survival in their final home game of the season against a Fulham side that had won just twice on their travels this season before Sunday.
But Birmingham looked nervous in the opening exchanges and their boisterous support was almost immediately quietened when Schwarzer's booming kick downfield bounced over Foster and was heading goalwards before the Blues keeper, who this week made himself unavailable for England duty, managed to scramble the ball away for a corner.
The home fans' relief was short-lived, though, as Jonathan Greening's centre from the resultant set-piece picked out Hangeland who powered into the six-yard box and headed into the net.
The visitors looked more likely to add to their lead with Greening, who was a constant menace in the first half, switching wings and delivering a succession of teasing crosses.
He first picked out Andrew Johnson but the striker guided his header inches wide, while Bobby Zamora's glancing header from a Greening free-kick grazed the post.
The Blues fans' cheers were turning to jeers of frustration as their side struggled to retain possession - their only brief moment of hope came when Martin Jiranek improvised well to chest Stuart Parnaby's cross goalwards, but his effort clipped the wrong side of the post.
Renewed cheers greeted Birmingham after the interval but once again the crowd was silenced by a quite astonishing Fulham onslaught.
It was almost like watching the Match of the Day highlights as first Zamora headed straight at Foster from close range and then moments later chipped an attempted lob straight at the keeper.
The striker, by that stage limping after appearing to sustain an injury, was replaced soon afterwards.
Within a minute of Zamora's miss Steve Sidwell's first-time shot from 16 yards rattled the post.
The goal that Fulham's pressure deserved duly followed, just four minutes into the half, Hangeland volleying in after the home defence failed to clear another Greening corner.
Foster kept the score down and Birmingham out of the relegation zone with a string of saves, denying Sidwell, Clint Dempsey and Johnson.
Had Birmingham conceded another goal, they would have dropped into the bottom three on goals scored - the Blues have notched just 36 this season, compared to Blackpool's 53 - adding extra importance to Foster's efforts which could prove crucial in seven days' time.