Dempsey celebrates the first of his two goals at Craven Cottage
Clint Dempsey grabbed a last-minute equaliser as Fulham denied Chelsea victory in a pulsating London derby.
Dempsey rose high to powerfully head past Petr Cech after it looked as though Frank Lampard's brace would be enough to earn Chelsea three points.
The American had flicked Fulham into an early lead before Lampard levelled with a cool finish following a mix-up.
Lampard's 30-yard free-kick put Chelsea ahead but Dempsey levelled to leave the Blues three points behind Liverpool.
After a shaky start at Craven Cottage it seemed as though Chelsea were destined to win thanks to a Lampard-inspired second-half display, but Fulham battled hard throughout and will feel they deserved their late reward.
Scolari laments Chelsea mistakes
Luiz Felipe Scolari, perhaps, will regret his decision not to start both Nicolas Anelka and Didier Drogba up front, with 14-goal Premier League top scorer Anelka left on the bench for their shortest away trip of the season.
Despite a bright Fulham start, Scolari's gamble nearly paid immediate dividends as the recalled Florent Malouda played Drogba through, but the big striker could only drag his shot tamely wide.
Shortly after, the Cottagers made him pay when Simon Davies swung over a free-kick, Chelsea's defence went to sleep and Dempsey had time to control at the far post and with his back to goal, divert the ball past Cech.
Fulham were proving more than a match for their more illustrious neighbours and the dropping of Anelka looked even more flawed when Drogba dragged another effort off target.
But on the half-hour mark Malouda limped off with a hamstring problem, Anelka replaced him and suddenly Chelsea were a different team.
Anelka had only been on the pitch for seconds when he forced Mark Schwarzer to save his stinging drive, while the Fulham keeper also had to be alert to tip over Lampard's swerving right-foot shot.
In-between, Chelsea suffered another injury when Alex hobbled off, with Ricardo Carvalho coming on for his first action in two months after a knee injury.
Scolari and his men did not want half-time to come, but they simply carried on in the same vein after the break and soon their pressure told.
Hodgson hails Fulham fighting spirit
Joe Cole sent a ball into the Fulham box and after Aaron Hughes and Schwarzer collided as they tried to prevent Drogba from scoring, the ball fell for Lampard to roll into the net.
Chelsea's tails were up and they attacked relentlessly for a goal to put them in front, Joe Cole twice forcing Schwarzer to save - the second a stunning parry low to his right.
When the goal did eventually come, the Australian goalkeeper will know he should have done more to prevent it.
Andrew Johnson fouled Deco and Lampard struck the free-kick low from 30 yards towards the bottom left-hand corner - but Schwarzer had crucially taken two steps to his right and could not quite get across in time.
It appeared as though Chelsea would comfortably see the game out, but Fulham - and Dempsey - had other ideas.
The pinpoint Davies swung over a corner from the right and Dempsey thumped his header past Cech into the far corner to send the home contingent in the 25,462 crowd into raptures.
Fulham manager Roy Hodgson:
"It was a fantastic fighting effort. Over 90 minutes Chelsea were the better footballing team, but we matched them in so many departments.
"In the second half Chelsea played really well and deserved to go 2-1 up.
"But credit to our players, they didn't lose their heads and they managed to score a wonderful late equaliser."
Chelsea boss Luiz Felipe Scolari:
"We had six, seven, eight chances to score and got two. They had two, from free-kicks, and scored twice.
"We had more possession, but we made two dangerous mistakes in our box and because of that we've lost two points, it really was just incredible.
"But we're in a good position, we just need to win games, nothing more."
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