Ten-man Chelsea suffered another setback in their stumbling season as they lost 4-1 at Watford on Monday after conceding three late goals to suffer their second straight Premier League defeat.
Daryl Janmaat, Gerard Deulofeu and Roberto Pereyra all scored late on after Eden Hazard had dragged Chelsea back into the game with a curling shot in the 82nd minute.
Mid-table Watford had taken the lead in the 43rd with a Troy Deeney penalty after Chelsea goalkeeper Thibaut Courtois brought down on-loan Barcelona winger Gerard Deulofeu.
By that stage, Chelsea were down to 10 men after midfielder Tiemoue Bakayoko was booked twice in the space of a few minutes before the half-hour mark.
Watford responded quickly to Hazard's equaliser as defender Janmaat exchanged passes with Pereyra before shooting past Courtois. Deulofeu sealed the win in the 88th before Pereyra put the icing on the cake with their fourth goal in added time.
Chelsea cruised to the title in coach Antonio Conte's first year in England last season but they are 19 points behind runaway leaders Manchester City and are focused on finishing in the top four Champions League qualification spots.
Chelsea sit in fourth spot, a point behind third-placed Liverpool and one ahead of Tottenham Hotspur in fifth.