West Ham remain in the hunt for automatic promotion after Ricardo Vaz Te's late penalty salvaged a point against fourth-placed Birmingham.
Blues looked set for victory when goals by Jordon Mutch, Marlon King and Chris Burke put them 3-1 up at the break.
But Sam Allardyce's side dominated after the break and Carlton Cole's low volley put them back in contention.
Vaz Te, who had earlier scored a header, then netted with a minute left as the points were shared.
The draw leaves the Hammers three points behind second-placed Reading, who take on Brighton on Tuesday night in their game in hand.
But the point will do little to appease those West Ham fans who have been frustrated with both the style of football played under Allardyce and a recent lack of form, which has seen the Hammers win just three of their last 10 games.
A win for Birmingham would have seen them close to within three points of Allardyce's side, but they remain firmly in the play-off places after a ruthlessly efficient first half in which they clinically took their chances.
Midfielder Mutch opened the scoring when he exchanged passes with King before advancing forward and rifling in a left-footed shot from 25 yards.
And King then doubled the lead three minutes later, breaking a static offside trap to run on and finish low past Robert Green.
Vaz Te gave the home side hope at the end of the first half, heading in from a corner to score in his fourth consecutive game.
But there was still time for Chris Hughton's men to take advantage of more dismal defending and score a third in stoppage time. A corner was only half cleared and when Burke hit a scuffed shot back through a pack of bodies the ball somehow found its way into the corner.
The home side were much improved after the break and pulled a goal back with 20 minutes left when Cole was afforded time and space inside the area to control Kevin Nolan's pass and drive into the far corner.
And they drew level when substitute Henri Lansbury's shot was handled by Chris Burke. Vaz Te took responsibility and drilled the penalty down the middle to secure a sixth draw in the last 10 games.
West Ham boss Sam Allardyce: "The players, when we set out to win a game of football, they need to be aware of what the opposition do and what they don't do and what we did was play straight into Birmingham's hands in the first half.
"There wasn't enough determination in the team by the players who defended that corner to say these boys are not going to score here at all costs.
"We've paid for a sloppy first half yet again and unfortunately while it's a magnificent comeback once again it's only one point and not three and three is what we wanted."
Birmingham boss Chris Hughton: "It's a good point here, you can only get the wins that you need to get and get the points that you need to get and you hope that some of the other results go for you.
"And I think the results of late have been good for us but whether we get into that top six or not won't be down to other teams it will be down to us. If we can keep the momentum we've got at the moment hopefully we'll be OK.
"It was tough to keep it going for 90 minutes but we are a team that have come here and scored three goals. There won't be many that do that this season.
"I've only got good things to say about my team and I thought we were excellent and well worthy of the draw - it's not easy playing two games in two games."