Chelsea suffered a major setback in their race to win the Premier League by dropping all three points against Crystal Palace.
The defeat gives Manchester City a major lift going into their game against Arsenal later today and gives Crystal Palace a five point lead over 18th-placed Cardiff City.
Jose Mourinho will be extremely disappointed with the result as his side failed to show up in what many had tipped to be a comfortable victory for the Blues.
Chelsea had the first chance of the match when Andre Schurrle was handed a golden opportunity to put his side 1-0 up with 18 minutes on the clock.
Cesar Azpilicueta went on a bombarding run down the left before crossing the ball to the German international who missed the target from just four yards.
Crystal Palace also had a terrific chance to open the scoring at a lively Selhurst Park when Yannick Bolasie was picked out by Jason Puncheon, however the Eagles winger was unable to poke the ball in from a tight angle.
The struggling south London side should have had a penalty moments after Bolasie’s mistimed effort as Cameron Jerome was hacked down from behind - leaving referee Lee Mason with a big decision to make.
However Mason decided not to award Tony Pulis’ side a penalty as he deemed Gary Cahill’s challenge on Jerome a fair one.
Crystal Palace upset the odds shortly after the interval when Joel Ward sent a dangerous ball into the direction of Jerome who was lurking on the edge of the box.
However it was Chelsea’s influential captain John Terry who diverted the ball past the helpless Petr Cech.
The unfortunate mistake by Terry was the defender’s first own goal since he put the ball into his own net against Bolton Wanderers in December 2003.
Mourinho threw on January signing Mohamed Salah on the back of Crystal Palace’s opener in hope that the Egyptian international could spark some life into the west London side.
However it was Crystal Palace who should have scored the second goal of the match as Puncheon came within whiskers of netting his first goal since signing a permanent deal with the club.
Jerome should have secured his side the three points when he was set free by Crystal Palace captain Mile Jedinak.
The Eagles loanee was allowed to run at Chelsea’s goal unchallenged but sent a low shot crashing against the woodwork.
Puncheon and Stuart O’Keefe came close to extending Palace’s lead but were foiled by Cech, however Terry’s own goal was enough to hand Pulis’ side the win.