With bigger fish to fry in Holland on Thursday night, a reshuffled Hammers took a bit of a battering at the Gtech Stadium, where they slumped to their 12th away defeat of the season.

First-half strikes from Bryan Mbeumo and Yoane Wissa gave Brentford the victory that guarantees them a top-half finish for 2022/23 and, while David Moyes and his men may not be mathematically safe from relegation just yet, the calculating, prioritising Scot made nine changes ahead of Thursday’s UEFA Conference League semi-final, second leg at AZ Alkmaar.

West Ham had crossed the capital riding on the high of a wonderful week that had seen them beat fourth-place Manchester United (1-0) last Sunday to go seven points clear of the relegation zone, before putting one foot into a richly-coveted European final with victory over the Dutch.

Wrapping a protective blanket around his squad ahead of crossing the North Sea for that last-four return, Moyes only retained Nayef Aguerd and Tomáš Souček in his starting line-up following the 2-1 win over AZ, while eight of Thursday’s starters dropped to the bench and Michail Antonio (calf) sat out altogether.

Predictably, Alphonse Areola had been replaced by Łukasz Fabiański, who became the first Polish player to make 350 Premier League appearances and the West Ham stopper would soon become the busiest man on the pitch, too.

With the new-look Hammers still getting acquainted with one another, during a messy, incohesive opening, it was Brentford who carved out the best of the early chances.

Indeed, the hosts forced two quick corners before then seeing Mikkel Damsgaard rise highest to meet Kevin Schade’s left-wing cross with a glancing header that flew beyond the far post before Thomas Frank’s side inevitably broke the deadlock on 20 minutes.

With Aguerd’s attempted pass putting Flynn Downes under too much pressure in the middle of the park, the ambushed Hammers midfielder could only watch as Brentford broke forward and, with Wissa squaring to Mathias Jensen, the Dane played in the unmarked, supporting Mbeumo who curled a low 15-yarder beyond Fabiański’s outstretched, groping glove and inside the base of the left-hand upright to claim his seventh goal of the season.

Coming into this encounter, honours had been even between these sides this campaign with the Bees winning the Premier League encounter at London Stadium in late December before West Ham triumphed in the FA Cup third round just eight days later at the Gtech Stadium.

But only Arsenal and Newcastle have departed fortress Brentford with all three points this season and with his side kicking off in 10th spot – 13 points and five places above the Hammers - Frank made a trio of changes from the team that had narrowly lost at Liverpool last time out, on Coronation Day.

In came Schade, Damsgaard and Wissa as Zanka and Frank Onyeka dropped to the bench, while injured 21-goal Ivan Toney missed out with a hamstring strain.

And, although Emerson climaxed a mazy run with a low 18-yarder that David Raya held, only a fine stop by Fabiański prevented Wissa from doubling the home advantage on the half-hour mark before Schade drilled another low effort just inches wide.

With the break approaching, West Ham's goal led a charmed existence when Jensen launched a long throw into the danger-zone and, with Fabiański punching Schade’s glancing header out from under the angle, neither Damsgaard nor Wissa could force the ball home before Ben Mee ended a frantic few moments of mayhem with an eight-yarder that was deflected behind.

The Hammers were not so fortunate on 41 minutes, though, when Jensen hurled another one of those massive throw-ins towards the penalty spot, where Mee glanced the ball towards the back post, leaving Wissa to ghost in front of Aguerd and nod inside Fabianski’s left upright to take his tally to a half-dozen for the season.

Still, the Hammers might have given themselves a lifeline in first-half stoppage-time, when the hitherto isolated Danny Ings finally forced Raya to tip his low 18-yard shot aside for the visitors first corner of the afternoon, but the red-faced Pablo Fornals typified a lacklustre opening 45 minutes when he curled his attempted flag-kick into the side-netting to ironic cheers from the home supporters.

After seeing Mbeumo’s point-blank header blocked by skipper Angelo Ogbonna, Moyes made a triple switch as Declan Rice, Divin Mubama and former Brentford favourite Saïd Benrahma replaced Souček, Maxwel Cornet and Fornals.

Still the Bees buzzed and still West Ham wobbled with Mbeumo nodding wide, Wissa curling beyond a post and Damsgaard sending a rising shot towards the River Thames from just a couple of yards out.

After Ben Johnson had made a rare appearance in the Brentford area, where he forced Raya to beat out his low 15-yarder, the Hammers right-back was soon back in opposing territory engineering the move that looked to have generated some Hammers hope.

Johnson whipped a deep ball crossfield to Benrahma, whose deep left-wing centre was met by fellow substitute Mubama at the far post and, although the hungry young striker could not force the ball into the net, Manuel Lanzini picked up the pieces and squared to Ings, who sidefooted home.

But a rare moment of joy for the 1,685 Hammers fans in the crowd of 17,075 was shortlived after referee Michael Oliver was referred to his pitch-side monitor, where he subsequently ruled that the unfortunate Mubama had handballed while attempting to avoid a collision with the right-hand upright.

That decision effectively extinguished all hopes of any unlikely Hammers comeback and, while the fully-employed Fabiański frantically kept the goal count down to two with some defiant late saves, everyone in claret and blue departed disappointed with this second-string showing, while eagerly anticipating the return of the first-team big guns at AZ Alkmaar on Thursday night (8pm).

Brentford: Raya, Pinnock, Damsgaard (Baptiste 76), Mee, Hickey (Roerslav 85), Henry, Jensen (Onyeka 68), Wissa (Dasilva 76), Janelt, Mbeumo, Schade (Ghoddos 86). Unused subs: Cox, Zanka, Ajer, Stevens.

West Ham United: Fabiański, Johnson, Emerson, Ogbonna, Aguerd, Downes, Souček (Rice 58), Cornet (Benrahma 58), Lanzini, Fornals (Mubama 58), Ings (Bowen 83). Unused subs: Areola, Cresswell, Zouma, Paquetá, Kehrer.

Booked: Hickey (76).

Referee: Michael Oliver.

Attendance: 17,075.