Chelsea were on the end of one of the shock results of the season as they fell to a 4-1 defeat at Watford.
The Hornets moved six points clear of the relegation places with the win, which was aided by the sending off of Tiemoue Bakayoko and a penalty conceded by Thibaut Courtois.
Troy Deeney opened the scoring from the spot after Courtois brought down Gerard Deulofeu, though Eden Hazard equalisde late on with a superb long-range strike.
However, there was still time for Daryl Janmaat to put the hosts back into the lead, before Deulofeu and Roberto Pereyra both scored to potentially hammer the final nails in Antono Conte's coffin.