Mark Flekken narrowly avoided disaster in the opening 30 seconds as he slipped but reached the ball before Michail Antonio could react, and it wasn’t long until Brentford were celebrating.
Neal Maupay hadn’t scored since facing the Hammers in September 2022, but the Frenchman was on hand to head in from Frank Onyeka’s scuffed attempt when the visitors were unable to convincingly clear their lines.
However, Mohammed Kudus responded with his second spectacular goal of the week, meeting Antonio’s cross with an acrobatic effort that left Flekken helpless.
The Ghanaian came close to a second goal of the afternoon when he directed Saïd Benrahma’s cross onto the post, but Jarrod Bowen reacted to turn home his seventh PL goal of the season - already surpassing his tally from last term - giving West Ham the lead just 15 minutes after they had gone behind.
Antonio poked the ball wide from Bowen’s cross with Benrahma waiting to tap it in what should have been the Hammers’ third, and they were almost made to pay with Bryan Mbeumo flashing two efforts agonisingly wide before the break.
Thomas Frank was forced to bring Thomas Strakosha on for the injured Flekken ahead of the restart, although he was a mere bystander for most of the half.
Alphonse Areola was beaten at the other end, as the threatening Mbeumo delivered a cross that Konstantinos Mavropanos headed into his own net on his first PL start since May 2019.
Brentford completed a turnaround of their own a quarter-hour later, as Nathan Collins rose to meet Mathias Jensen’s cross with a towering header for his first goal since April 2022.
The Hammers looked for an equaliser but Pablo Fornals blazed his effort over the crossbar from the edge of the box, as Brentford secured their third consecutive victory after winning just one of their first eight PL matches this campaign - doing so despite Maupay missing a late opportunity to give them a buffer.
West Ham, meanwhile, have lost three league games in a row for the first time this season.
Flashscore Man of the Match: Bryan Mbeumo (Brentford)
