Brighton and Hove Albion were beaten at Brentford after a brace from Bryan Mbeumo and goals from Yoane Wissa and skipper Christian Norgaard.
Danny Welbeck and Kaoru Mitoma replied but a red card for Joao Pedro and an injury to Jan Paul van Hecke added to the misery on a disappointing afternoon in west London.
Albion conceded an early goal – after nine minutes – as Mbeumo chased a penetrating pass by Keane Lewis-Potter, dispatched from the halfway line.
The Cameroon international outpaced Pervis Estupinan and Van Hecke and finished with a well-struck shot that an outstretched Bart Verbruggen was unable to stop.
Welbeck equalised on the stroke of half time – his ninth of the season – heading home an inch-perfect ball into the area from Mats Wieffer.
Moments after the break the Bees went in front again. Wissa played the ball back to Mbeumo and, from just inside the area, his solid strike appeared to take a deflection off Brighton captain Lewis Dunk to leave Verbruggen with no chance.
Wissa made it three just before the hour. Mbeumo sprinted away down the right flank before squaring the ball which again deflected – off Van Hecke and possibly Dunk too – wrong-footing the keeper.
In the 61st minute the game changed completely after a straight red card for Pedro for violent conduct for striking out at Nathan Collins in an off-the-ball tussle.
Ten-man Albion pulled one back in the 81st minute. Solly March passed to Jack Hinshelwood who set up Mitoma. The Japan international fired a shot from a tight angle past Mark Flekken in the Brentford goal.
Five minutes into second-half stoppage time, Norgaard headed in the fourth Brentford goal from a Mathias Jensen free kick.
A few minutes later Van Hecke and Yunus Konak clashed heads and, after about 10 minutes, the Albion defender was stretchered off and taken to hospital. He was later discharged.
The defeat leaves Albion in 10th place in the Premier League, with 48 points from 33 games, two points ahead of Brentford in 11th.
Pedro will miss home games against West Ham United, next Saturday (26 April), and Newcastle United, on Sunday 4 May, as well as the trip to Wolverhampton Wanderers, on Saturday 10 May.
And the prospect of Albion playing European football next season looks increasingly remote.