Chelsea crashed to a fifth successive defeat under Frank Lampard as their west London neighbours Brentford won 2-0 at Stamford Bridge.
In his second spell as Chelsea boss after replacing the sacked Graham Potter until the end of the season, Lampard has failed to spark a revival from his troubled team, who were booed off at full-time.
With former Paris Saint Germain and Tottenham manager Mauricio Pochettino reportedly close to taking charge, Chelsea are enduring their worst run since 1993 after their winless streak extended to eight games.
Cesar Azpilicueta’s 37th minute own goal and Bryan Mbeumo’s 78th minute strike left 11th placed Chelsea in danger of finishing in the bottom half of the table for the first time since 1996.
Liverpool kept alive their slender hopes of a top four finish with a 2-1 win at West Ham.
The Hammers took a 12th-minute lead through Lucas Paqueta’s spectacular strike, only for Cody Gakpo to equalise from long-range five minutes later.
Joel Matip’s 67th minute header moved sixth placed Liverpool within six points of fourth placed Manchester United, who have two games in hand.
Nottingham Forest climbed out of the relegation zone as they beat Brighton 3-1 at the City Ground to win for the first time in 12 games.
Brighton took the lead in the 38th minute through Facundo Buonanotte’s first Premier League goal, but Forest equalised thanks to Pascal Gross’s 45th minute own goal.
Danilo netted after 69 minutes before Morgan Gibbs-White’s late penalty lifted Forest one point clear of the bottom three.