The Hammers were stung by the Bees at London Stadium, where substitute Yoane Wissa condemned David Moyes men to defeat with the stoppage-time winner that also saw the West End boys leapfrog the East Enders in the Premier League table.

Thomas Frank’s side had deservedly taken an interval lead through Bryan Mbeumo before Jarrod Bowen looked to have secured a point ten minutes from time but Wissa’s fifth goal in six matches since his August arrival from French side Lorient gave the visitors the late, late victory that left the Hammers boss suffering his 200th Premier League loss.

Following Thursday night’s Europa League victory over Rapid Vienna, in-form West Ham had made seven changes as they returned to league action having lost just once in their opening half-dozen matches.

Bowen, Łukas Fabiański, Angelo Ogbonna, Kurt Zouma, Tomáš Souček, Pablo Fornals and fit-again Vladimír Coufal each returned to face a Brentford side kicking-off in 10th-spot, just three places and two points behind West Ham United,

The newly-promoted Bees had also lost just one in their first six games following their return to the big time after a 74-year absence and, with last weekend’s determined 3-3 draw against Liverpool underlining how they have attacked their top-flight adventure, the Hammers also found themselves on the back foot early on.

Having shared the points with the Reds eight days earlier, Frank made two changes as Shandon Baptiste and Zanka came in for Kristoffer Ajer and Vitaly Janelt, who was injured in the warm-up but that late enforced switch clearly had little effect on the visitors in the opening exchanges.

Mbeumo served up due notice of his intentions when he tickled Fabiański’s crossbar with a dipping 18-yarder with just a couple of minutes or so on the clock and, shortly afterwards, the Brentford striker headed Rico Henry’s cross inches wide.

Then, on 10 minutes the Hammers’ ‘keeper was forced to claw Ivan Toney’s 12-yarder aside as Moyes boys struggled to find any cohesion with the Bees swarming forward at every opportunity.

In reply, the men in Claret & Blue did finally threaten on the quarter-hour mark, when Aaron Cresswell whipped over a deep right-wing corner which Zouma headed inches wide at the far post.

But that would only prove to be token resistance during Brentford’s barnstorming start and, sure enough, on 20 minutes they inevitably broke the deadlock when Toney slipped Sergi Canós in behind the Hammers defence.

Although Fabiański managed to brilliantly beat out the Spaniard’s low, angled eight-yarder, before recovering to parry Mbeumo’s follow-up, the Polish stopper was adjudged to have been behind his goal-line and – by the fine margin of just a centimetre of so - referee Bankes signalled the Frenchman’s third goal of the season.

After Mathias Jensen replaced Baptiste, who had been forced to retire with an arm injury having fallen awkwardly, Zouma was then booked for tripping the tenacious Toney on the edge of the Hammers area.

But as the first-half drew to a close West Ham finally started to launch a few assaults of their own via former Brentford favourite Saïd Benrahma, who fired into David Raya’s gloves before then curling a 20-yarder inches agonisingly wide of the right-hand upright, while Michail Antonio also hooked over to leave Frank’s side with their one-goal advantage intact, going into the break.

Just after the restart, Benrahma was again trying his luck – this time with a 20-yard free-kick that Raya tipped over the bar after it fizzed above the Brentford wall, while Coufal slashed well wide from similar range before Bowen’s angled shot was charged down at point-blank range by the Spanish stopper.

Bowen then nodded Coufal’s inviting cross wide of the far post before the Czech right-back’s own angled effort was deflected behind and, as the Hammers began to give a better account of themselves, Christian Nørgaard was booked for tugging back Fornals.

With Brentford’s central-defensive trident of Zanka, Pontus Jansson and Ethan Pinnock forming an all but impenetrable wall of yellow, West Ham appeared to be running out of time and ideas but with just ten minutes remaining that Bees barrier was finally breached.

When Cresswell sent over another inviting corner, Pinnock could only half-clear skipper Declan Rice’s corner and Bowen raced in to connect with the loose ball which he drilled powerfully inside the base of Raya’s left-hand upright from 12 yards to claim his first goal of the campaign.

That East End exocet finally silenced the West End boys, whose frustration at finally losing their advantage saw both Canós and Zanka booked for fouls on Fornals and Antonio, while Rice also took one for his team to prevent Wissa escaping.

And with the game heading into the third and final minute of stoppage-time both teams looked destined to take a point apiece.

The Bees, however, had other ideas and when Canós floated over a free-kick from the right-hand edge of the Hammers area, skipper Jansson saw his header athletically beaten out by Fabiański but sadly for everyone in Claret & Blue, danger still lurked in the shape of substitute Wissa, who unleashed an unstoppable 12-yarder back through the pack to almost rip the goal-net off its hooks and bag all three points for Brentford.

West Ham: Fabianski, Coufal, Cresswell, Zouma, Ogbonna, Rice, Souček, Fornals, Benrahma, Bowen, Antonio. Unused subs: Areola, Yarmolenko, Lanzini, Vlašić, Dawson, Diop, Masuaku, Johnson, Král.

Brentford: Raya, Zanka, Jansson, Pinnock, Baptiste (Jensen 28), Nørgaard, Onyeka (Bidstrup 81), Canós, Henry, Mbeumo (Wissa 81) Toney. Unused subs: Fernández, Goode, Forss, Ghoddos, Roerslev.

Booked: Zouma (35), Nørgaard (68), Canós (83), Zanka (85), Rice (90+1).

Referee: Peter Bankes.