Jose Mourinho has admitted he his worried about Chelsea's Premier League title challenge after defeat to Stoke City on Saturday, saying the Blues are "in trouble".
John Terry led the Stamford Bridge side to the Britannia Stadium on his 33rd birthday but he did not get the present he would have been hoping for, as Mark Hughes' side pulled off a huge shock.
Chelsea were in control early on and looked to be cruising to half time with a 1-0 lead thanks to Andre Schurrle's opener - which was one facet of a fine display by the Germany international - but another Petr Cech mistake allowed Peter Crouch to equalise.
Schurrle scored a second to restore parity after the Blues had fallen behind at the start of the second half through a Stephen Ireland strike.
Mourinho would have expected his side to go on and take the game away from their opponents, but failed to capitalise on their dominance and the Potters fans were delirious when substitute Oussama Assaidi fired home a rocket into the top corner to secure all three points.
Defeat meant Chelsea are level on points with Liverpool and remain four points behind leaders Arsenal, who can extend that margin to seven points on Sunday when they host Everton at Emirates Stadium.
Mourinho could not put a positive gloss on the Blues' performance and admitted his concern after the game.
"I don’t feel comfortable enough to tell you what I think about the game. We’re in trouble," he told reporters.
"After 30 minutes we should have been winning 3-0 or 4-0 but we weren't. You have to kill the game, but we didn't."