LONDON - Chelsea's recovery under Rafa Benitez was brought to a shuddering halt by Queens Park Rangers on Wednesday as the Premier League's bottom team won 1-0 in the west London derby.
QPR's first win in the top flight at Stamford Bridge since March, 1979 was secured by a Shaun Wright-Phillips goal against his former club.
The end of Chelsea's four-game winning run in one of the biggest shocks so far this season left Benitez's side fourth in the standings.
Everton are only two points behind after beating Newcastle 2-1, but have played a game more than both Chelsea and sixth-place Arsenal.
Liverpool still have their sights on the top four, beating Sunderland 3-0 to move seven points behind Chelsea but having played an extra match.
Rafa Benitez's decision to make five changes from the Chelsea side that beat Everton at the weekend appeared to backfire, with Chelsea struggling to impose themselves with the likes of Eden Hazard and Juan Mata watching from the bench.
"We cannot carry on with the same players every game," Benitez said.
"If you are playing a team that is bottom of the table at home you have to trust your players."
QPR's breakthrough came when David Luiz only half-cleared a corner in the 78th minute, and Adel Taarabt teed up Wright-Phillips to smash the ball into the net of the team he left in 2008.
QPR remain bottom but are now only behind Reading on goal difference, although the team remain eight points from safety.
"I can't remember having many better wins than this," QPR manager Harry Redknapp said.
"Chelsea are absolutely flying at the moment and, on the back of our defeats against Liverpool and West Brom, it was a great result for us."
Ahead of the match, Chelsea was closing in on a deal to bolster their striking options by signing Demba Ba from Newcastle after offloading Daniel Sturridge to Liverpool.