Shaun Wright-Phillips ensured Harry Redknapp's side made the best possible start to 2013, with the ex-Chelsea winger returning to haunt his former employers with a stinging drive which moved QPR level on points with Reading and five adrift of safety.
Marko Marin, making his first start for Chelsea, was extremely lucky to escape a fourth-minute red card from referee Lee Mason after driving into the shin of Stephane Mbia with a one-footed, studs-first challenge.
QPR then suffered a setback when Junior Hoilett limped off in the 16th minute with what appeared to be a hamstring problem, resulting in Wright-Phillips' arrival from the bench.
The visitors rarely escaped their own half during the opening period, but defended resolutely with skipper Clint Hill nodding clear a curling shot from Oscar.
Chelsea then lost their way in the 10 minutes before half-time, the result of a lack of urgency and series of errors, but shots from Oscar and Frank Lampard brought them back to life.
Victor Moses wasted a glorious chance three minutes after the interval when he steered Marin's fast pass wide when only four yards out.
QPR's goal was coming under growing pressure with Branislav Ivanovic grazing the crossbar, David Luiz seeing a rocket blocked and only a brave save by Julio Cesar denying Fernando Torres from point-blank range.
Adel Taarabt and Wright-Phillips combined superbly to tee up Esteban Granero but the Spaniard's shot was plucked from the air by goalkeeper Ross Turnbull, who started ahead of groin injury victim Petr Cech.
QPR were now in the ascendancy with Jamie Mackie denied a one on one with Turnbull by a last-ditch tackle from Gary Cahill before Shaun Derry's header was caught by the Chelsea goalkeeper.
Lampard then stabbed the ball home but the flag had been raised for offside in what was a close, but correct, call.
Once again Chelsea faded and this time QPR took advantage, working the ball from a corner via Taarabt to Wright-Phillips, who drove the ball into the bottom left corner of the net from the edge of the area.
Ivanovic nodded over the crossbar in the dying moments and QPR held on for a precious three points.
|Chelsea||Team Statistics||Queens Park Rangers|
|0||1st Half Goals||0|
|2||Shots on Target||3|
|13||Shots off Target||3|
|61||1st Half Poss.||39|
|67.7||2nd Half Poss.||32.3|