At a glance
Crysencio Summerville scores the only goal of the game to seal vital win for West Ham
The winger's strike comes after both sides had penalty appeals waved away
West Ham move level on points with Nottingham Forest, while Fulham slip to 10th
Crysencio Summerville scored the only goal of the game as West Ham boosted their hopes of Premier League survival with a hard-fought win against Fulham at Craven Cottage.
The Dutchman pounced on a lapse in communication between Bernd Leno and Calvin Bassey shortly after the hour mark to earn the struggling Hammers only a seventh win of the Premier League season.
After Nottingham Forest's 2-2 draw with Manchester City on the same night, the three points moves Nuno Espirito Santo's side level on points with the Midlands club who sit in 17th place.
The defeat is a blow for Fulham's hopes of qualifying for Europe as they slip to 10th after failing to capitalise on Liverpool and Bournemouth's dropped points 24 hours earlier.
With Fulham missing talisman Harry Wilson and West Ham among the lowest scorers in the Premier League, the first half drifted towards a stalemate before sparking into life late on at Craven Cottage.
Valentin Castellanos and Samuel Chukwueze exchanged efforts inside the opening five minutes, while the Hammers had a penalty appeal waved away when Jarrod Bowen's corner struck the shoulder of Alex Iwobi.
But the contest finally burst into action in the closing moments of the half when West Ham midfielder Mateus Fernandes narrowly avoided a second yellow card for a foul on Joshua King.
King should have opened his account in the Premier League seconds later as his shot was saved by Mads Hermansen after stealing a yard on Tomas Soucek inside the box.
Fulham were then awarded a penalty four minutes into the second half when Tom Cairney went to ground under a challenge from Castellanos
However, referee Matt Donohue overturned the decision after consulting the pitch-side monitor, ruling that Cairney had in fact kicked the West Ham forward.
The breakthrough came in the 65th minute when Summerville took advantage of a mix-up between Leno and Bassey before finishing coolly for his fifth goal of the campaign.
Hermansen produced a stunning save four minutes from time to deny Timothy Castagne and earn his side a precious derby victory.
Fulham analysis: A bad night from start to finish
'The incidents dictated the result' - Silva frustrated after West Ham loss
For Fulham, it was a night that began badly and never truly recovered.
The pre-match news that Harry Wilson would miss out through injury heightened the challenge facing Marco Silva's side.
The 28-year-old Wales international has been a talismanic figure for the Whites this season.
Wilson is the first Fulham player since Dimitar Berbatov in 2012-13 to register 15 goal contributions in a single campaign, so his absence was always likely to be felt.
But with his contract set to expire this summer, Wednesday night offered a glimpse of what life without him could look like at Craven Cottage.
On the basis of this performance, Silva's side will need to find new source of attacking threat in the final third if they are to continue to fight for Europe.
West Ham analysis: Summerville offers Hammers a glimmer of hope
Nuno Espirito Santo praises his side's fight as West Ham beat Fulham
On a night when West Ham unveiled a new-look strike partnership, it was Summerville who grabbed the headlines.
For the first time since December, Nuno opted for a front two - Castellanos and Callum Wilson - in an attempt to spark his side's survival bid.
But it was Summerville who continued his mission to keep the Hammers afloat, finishing with the composure of a veteran at Craven Cottage.
Since the turn of the year, the 24-year-old has scored seven of West Ham's 17 goals in all competitions - with five of them coming in the Premier League.
After a difficult first 18 months following his £25m move from Leeds in 2024, the winger has emerged as a beacon of hope for Hammers supporters in recent weeks.
For 14 minutes on Wednesday night, his strike had lifted his side out of the relegation zone - at Nottingham Forest's expense - for the first time since December.
Although Forest later fought back to claim a point against Manchester City at the Etihad, West Ham have the Midlands club in their sights and are only a point behind Tottenham who host Crystal Palace on Thursday.
If the Hammers are to beat the drop and preserve their Premier League status, Summerville is likely to have a decisive say.
Player of the match
After the opportunity to rate players has closed, the score displayed represents the average from all the submissions by BBC Sport users.