Chelsea's title hopes suffered a major blow with a shock 2-1 home loss to bottom side Sunderland as manager Jose Mourinho suffered a Premier League defeat at Stamford Bridge for the first time.
Fabio Borini, on-loan from league leaders Liverpool, scored the winner with a penalty in the 82nd minute after Cesar Azpilicueta brought down Jozy Altidore, bringing an end to Mourinho's record of 77 unbeaten home league outings with Chelsea.
Sunderland's Connor Wickham had equalised in the 18th minute to cancel out Samuel Eto'o's early opener.
The defeat left Chelsea in second spot on 75 points from 35 games with three matches left, two points behind Liverpool who have played 34 and visit Norwich City on Sunday.
Sunderland, who drew with third-placed Manchester City in midweek, stay bottom with 29 points, one behind Fulham and Cardiff City with a game in hand, and three off Norwich who are just above the relegation zone in 17th.