Bryan Mbeumo and Yoane Wissa strikes kept Brentford in the hunt for European football next season as West Ham were beaten.
Both goals arrived before half-time at the Gtech Community Stadium as the Hammers, in the middle of their Europa Conference League semi-final, were second best.
Danny Ings saw a second-half reply chalked off by VAR after Divin Mubama was adjudged to have handled the ball after it bounced off the post.
More to follow
Bryan Mbeumo celebrates scoring Brentford's opening goal against West Ham on Sunday
The Bees broke the deadlock at the Gtech Community Stadium thanks to Mbeumo
Yoane Wissa (right) celebrates with Kevin Schade after doubling Brentford's advantage
Wissa finishes to put Brentford in firm control of the contest just two minutes before half-time
West Ham were left to rue their shoddy defending after Wissa doubled Brentford's lead
Danny Ings thought he'd halved the deficit for West Ham but VAR disallowed the goal
Divin Muamba handballed as the ball came off the post, before Ings turned the ball into the net
Referee Michael Oliver breaks the bad news to goalscorer Ings after the VAR review
Yoane Wissa goes down in the box under a challenge by West Ham's Angelo Ogbonna
Ben Mee reacts after a chance goes begging during the first-half of the contest in west London
Match facts and ratings
Brentford (4-3-3): Raya (c); Hickey (Roerslev 86), Pinnock, Mee, Henry; Damsgaard (Baptiste 78), Jensen (Onyeka 70), Janelt; Mbeumo, Wissa (Dasilva 77), Schade (Ghoddos 86)
Substitutes not used: Cox (GK); Zanka, Ajer, Stevens
Manager: Thomas Frank
Scorers: Mbeumo 20; Wissa 43
Booked: Hickey
West Ham United (4-2-3-1): Fabianski (c); Johnson, Ogbonna, Aguerd, Emerson; Soucek (Rice 58), Downes; Fornals (Mubama 59), Lanzini, Cornet (Benrahma 58); Ings (Bowen 84)
Substitutes not used: Areola (GK); Cresswell, Kehrer, Paqueta, Zouma
Manager: David Moyes
Referee: Michael Oliver