Chelsea's run of good form came to an abrupt end on Wednesday as the London side were defeated 1-0 by city rivals QPR.
It was a huge result for QPR who remain bottom of the table and a costly reminder to Chelsea manager Rafa Benitez that there are no easy games in the Premier League.
Interim coach Benitez made five changes to his starting line-up, with Ashley Cole, Ramires, Juan Mata, Eden Hazard and the injured Petr Cech dropping out, and the changes were to prove costly.
Shaun Wright-Phillips' goal against his former side gave QPR their first victory at Stamford Bridge in 30 years.
Wright-Phillips struck the ball into the bottom corner of the net in the 78th minute to halt Chelsea's run of four successive wins and leave their west London rival in fourth place.
QPR remain bottom but are now only behind Reading on goal difference.
Luis Suarez scored twice and set up another goal as Liverpool beat Sunderland 3-0 to win consecutive Premier League matches for only the second time this season.
On the same day Liverpool bought Daniel Sturridge to ease the scoring burden on Suarez, the Uruguay forward found the net in the 26th and 52nd minutes for his 14th and 15th league goals of the season - one behind leading scorer Robin van Persie.
Raheem Sterling gave Liverpool a 1-0 lead in the 19th at Anfield after receiving Suarez's lobbed pass and then calmly chipping the goalkeeper.
Liverpool, who won 3-0 at QPR on Sunday, have now risen two spots to eighth in the standings, seven points behind fourth-place Chelsea but having played a match more.
Sunderland stayed 14th, four points above the relegation zone.
In the other game of the night, high flying Everton started 2013 with a win after coming from behind to defeat Newcastle 2-1.
Papiss Cisse did his best to prove there is life after his Senegal team-mate Ba - who is expected to move to Chelsea - at Newcastle by heading the hosts into a second-minute lead after goalkeeper Tim Krul's long kick was allowed to bounce on the edge of the visitors' box.
Leighton Baines produced a goal-of-the-season contender to equalise, however, rippling the net with a magnificent 30-yard free-kick that left Krul grasping at thin air.
Substitute Victor Anichebe completed the comeback on the hour, tapping in Nikica Jelavic's low cross barely ninety seconds after coming on to send Everton up to fifth.
Meanwhile Newcastle sit only two points above the relegation places.