Chelsea suffered their fifth loss in as many games under interim manager Frank Lampard in their 2-0 defeat to Brentford at the Stamford Bridge.
Cesar Azpilicueta scored an own goal in the 37th minute before Bryan Mbeumo doubled the lead for the Bees in the 78th minute of what was a lifeless display from the Blues.
Noni Madueke came close to pulling one back in the 92nd minute but his header glanced right and wide of the post.
The 5 defeats, during which they have scored just once and conceded 9 goals, is their longest run of defeats since November 1993.
Chelsea have now also lost their 13th game of the Premier League season. They have only lost more in one 38-game PL campaign: 15 in the 1997-98 season.
They are stuck in 11th position with 39 points from 32 games haven accrued just 10 wins this season with 4 of those coming in the last 23 games.
Thomas Frank’s Bees have amassed 47 points from their 33 games played so far.
Meanwhile, away from London and in the City Ground, Nottingham Forest pulled a polished display to defeat Brighton 3-1 in their quest to beat the drop.
Brennan Johnson missed his penalty kick in the 11th minute and Buonanotte put Brighton in the lead in the 38th minute.
An own goal from Pascal Gross, a Danilo goal and Morgan Gibbs-White’s penalty saw Steve Cooper’s side earn their 30th point of the season to find themselves in 17th place.
Cody Gakpo and Joel Matip scored as Liverpool pulled a comeback to defeat WestHam United who had gone ahead in the 12th minute via a Lucas Paqueta goal.
The win keeps the Reds in sixth with 53 points – just six adrift of Manchester United who are in fourth having played two games less.