Eidur Gudjohnsen scored against his former Chelsea team mates to put Barcelona 2-1 up after 58 minutes but Chelsea struck back just before the finish to steal a point.

The result makes Chelsea almost certain of progress but jeopardises the European champions' chances of making a successful defence of their crown. They now drop to third place in the group two points behind Werder Bremen and five behind Chelsea after the Germans won 3-0 at Levski Sofia.

Barca got off to a dream start when midfielder Deco, a former pupil of Jose Mourinho's at Porto, cut in from the left, sped towards the area and unleashed a low drive that fizzed into the net past the outstretched Hilario in the second minute.

Ronaldinho should have made extended the lead six minutes later after Lionel Messi sped past the Chelsea back four following a neat one-two with Gianluca Zambrotta.

But the Brazilian skied his shot over the bar after the Argentine teenager had cut a neat pass into his path from the byline.

Stand-in goalkeeper Hilario came to Chelsea's rescue 15 minutes later when he produced a fine full-stretch save to turn a stinging shot from Xavi past the post after the midfielder had exchanged passes with Ronaldinho.

Chelsea came out firing on all cylinders after the break and Dutch winger Arjen Robben gave Barca two more scares, Valdes producing another sharp save to stop a close-range header and the Dutchman firing over the bar after a great combination between Frank Lampard and Ashley Cole.

But the Londoners had little time to bemoan the miss as Lampard, who had earlier picked up a booking that will see him miss the next match against Werder, put them back on level terms with a remarkable goal.

The England midfielder beat the offside trap to pick up a lofted pass from Essien appeared to have taken the ball too wide, but he swivelled round on the byline and dinked the ball over Valdes and into the far corner from a seemingly impossible angle.

Barca restored their lead six minutes later when Gudjohnsen steered in from five metres out after Ronaldinho had darted down the left flank and curled in a tempting cross with the outside of the boot.

The referee, kept busy all night by constant diving, debating and fouling of both sets of players, allowed five minutes of added time, and Drogba, who scored the winner two weeks ago at Stamford Bridge, took full advantage.

The Ivory Coast striker expertly chested down a headed pass from John Terry to make space in the area and then fired a shot under Valdes to snatch the point.

Chelsea manager Jose Mourinho was beaming with pride at the end.

"Everything is in our hands now but I am very proud of the performance," said the Portuguese maestro, who had as usual stirred things up by alleging Gudjohnsen had learnt to dive since he joined Barcelona.

"We had five or six big chances.

"I believe we had two penalties in our favour. We made life difficult for us as we conceded a goal so early."