Honours were even in the Boxing Day battle of the Blues, with Chelsea squandering a host of chances to take all three points but grateful to an errant referee’s assistant for the one.

Carlo Ancelotti’s men were ultimately denied by a fine display from Birmingham keeper Joe Hart, who kept the first clean sheet against Chelsea in this season’s EPL.

On the rare occasions when Hart was out of the picture, Chelsea were wasteful, Daniel Sturridge and Florent Malouda the guilty parties.

And Malouda’s day got worse when he was dismissed after his second bookable offence as the game entered stoppage time.

Cameron Jerome stretched Chelsea’s back line before shooting over the bar in the game’s first attack, but Chelsea quickly dominated possession.

Hart made a fine left-handed stop from Sturridge’s low drive on 22 minutes and conjured up an even better one from Frank Lampard’s left-foot volley five minutes later.

Chelsea should have gone behind on the half-hour mark when Dean Ridgewell’s right-foot shot was turned in by Christian Benitez, who was flagged offside despite being level with Didier Drogba, lying injured in the six-yard box, and behind the ball.

But Alex shook the Birmingham crossbar to its roots with a stunning 35-yard free-kick on 39 minutes and Sturridge side-footed wide from close range with an excellent chance in first-half stoppage time.

Chelsea keeper Petr Cech did well to keep out Sebastian Larsson’s free-kick after an hour, crashing into his post in the process.

But Hart was soon the star again, denying Kalou eleven minutes later with another fine left-handed stop; although Malouda spurned the best chance of the half moments earlier, spooning his right-foot shot horribly off-target after Kalou had set him up.

And the French striker saw yellow for the second time for a late challenge on Stephen Carr, leaving Chelsea to hold out during six minutes stoppage time with ten men.