West Ham's survival hopes were dented by a heavy 5-2 defeat to Liverpool at the weekend, although they would have taken some inspiration from that taking their record to two or more goals scored in five consecutive outings.
Their attacking intent was on display again inside the first minute when the Hammers created the opening for Taty Castellanos to force Bernd Leno into early action.
In contrast, Fulham took their time to offer a real attacking threat as they struggled to adapt to the absence of the talismanic Harry Wilson, who picked up an ankle injury in Sunday’s win over Tottenham Hotspur.
The patient Cottagers finally carved open a golden opportunity in first-half stoppage time when Joshua King cleverly worked the space to unleash a low shot that was kept out by Mads Hermansen's outstretched right boot.
Like the first period, Leno was called into action within a minute of the referee’s whistle, reacting smartly to tip Tomáš Souček’s header over the crossbar.
Just moments later, the Hammers breathed a collective sigh of relief when the referee overturned his original decision to award the Cottagers a penalty, with VAR showing that Tom Cairney kicked through Castellanos rather than the contact coming from the West Ham marksman.
Nuno Espírito Santo’s side quickly put their scare behind them as Summerville whipped in a dangerous delivery that should have been finished off by Callum Wilson at the far post.
The confident Summerville soon demonstrated the composure that Wilson lacked, pouncing on a mix-up between Leno and Calvin Bassey before shimmying past Sander Berge to curl home a left-footed shot to the delight of the away support behind the goal.
Hermansen then pulled off a vital late save to thwart Timothy Castagne and seal a win that means only goal difference keeps the PL’s 18th-placed side behind Nottingham Forest, while they move within a point of Spurs.
As for Marco Silva’s charges, the defeat keeps them in 10th spot and eight points adrift of the top six.
Flashscore Man of the Match: Crysencio Summerville (West Ham United)
