LONDON — In another twist to this unpredictable English Premier League season, last-place Sunderland damaged Chelsea's title hopes with a 2-1 upset at Stamford Bridge on Saturday.
After surprise losses to Aston Villa and Crystal Palace in recent weeks, Chelsea again stuttered against weaker opposition, as Jose Mourinho's 77-match unbeaten home run as Chelsea boss came to an end in a major boost for league leader Liverpool.
Chelsea could not hold onto its lead after Samuel Eto'o opened the scoring, as Connor Wickham leveled from the rebound six minutes later following Marcos Alonso's long-range effort. Fabio Borini then scored from the spot after Cesar Azpilicueta brought down United States forward Jozy Altidore in the box with eight minutes remaining.
Elsewhere, Crystal Palace claimed a fifth consecutive win with a 1-0 defeat of West Ham to secure its place in the topflight next season and Swansea secured a vital 2-1 win at Newcastle that piled more pressure on Magpies manager Alan Pardew.
Peter Whittingham's second-half penalty gave Cardiff a precious point in a 1-1 draw against Stoke, and Aston Villa could record only a goalless home draw with Southampton.
Sunderland goalkeeper Vito Mannone made 14 saves as Chelsea blew the opportunity to dislodge Liverpool from top spot. The Reds will have the chance to extend their lead to five points at Norwich on Sunday.