Raul Jimenez deepened West Ham’s relegation worries as Fulham snatched a 1-0 victory at the London Stadium.
The Mexican struck with five minutes remaining, with his second goal in two matches giving Fulham a third straight win.
Manchester City’s lunchtime victory at Nottingham Forest gave the Hammers the chance to cut the gap to 17th place to just two points.
But instead they remain five points adrift of safety after the first of a run of supposedly winnable games, with Brighton and Forest still to come to east London, either side of a trip to rock-bottom Wolves.
There was little festive good cheer in the air at the London Stadium, with West Ham supporters holding up red cards and chanting “sack the board” in the latest protest against owner David Sullivan and vice-chair Karren Brady.
On the pitch, the Hammers have won just two matches at home this season, lost their last six London derbies and taken just three points from their last seven games, which is definitely relegation form.
Jimenez, who scored Fulham’s winner against Forest before Christmas which lifted them well clear of any imminent danger, had their first chance but curled his effort wide.
Moments later, in-form midfielder Harry Wilson let fly from 20 yards with Alphonse Areola at full stretch to tip the ball over.
West Ham threatened when Mateus Fernandes threaded the ball to Jarrod Bowen, whose angled shot was saved by Bernd Leno.
Then a slick Hammers move down the right saw Kyle Walker-Peters send Crysencio Summerville to the byline, and his cross was headed narrowly wide by Ollie Scarles.
Summerville had a volley deflected wide from a Freddie Potts corner before, at the other end, Areola had to make an unorthodox save with his feet to keep out Joachim Andersen’s long-range effort.
Fulham should have taken the lead seven minutes into the second half when Wilson darted into space down the right, but his low cross eluded both Kevin and Sasa Lukic in front of goal.
The chances were by now coming at both ends with Lukic heading an inviting Antonee Robinson cross wide, before Bowen somehow scooped a cross from Soungoutou Magassa off target from six yards out.
Callum Wilson, on as a sub, turned Andersen on the halfway line and raced towards goal but his shot flew wide.
Bowen teed Wilson up for another shooting chance, but this time he lifted it over the top.
Instead it was Fulham who took the points after a mistake by the otherwise impressive Scarles, who took an air-shot at a clearance, allowing Wilson to lift a cross to the far post for Jimenez to win it.
