Chelsea succumbed to a first home defeat against neighbours Queens Park Rangers since 1983, thanks to a late goal from Shaun Wright-Phillips.
After a stale first half, Chelsea came out hungrier in the second period and more than once looked like opening the scoring, only for a sucker punch from former Blue Wright-Phillips, who had been introduced as a first-half sub.
Chances fell to Fernando Torres and Branislav Ivanovic in particular, but found visiting goalkeeper Julio Cesar in top form, and our visitors a more defiant opposition than they have been in recent months.
The result leaves us in fourth place, still a point adrift of third-placed Spurs, but with a game in hand.
Petr Cech was missing for the first time in the Barclays Premier League this season due to the injury sustained at Everton on Sunday, so his deputy Ross Turnbull was in his place.
Elsewhere Rafael Benitez opted to rotate with Marko Marin starting his first league match since arriving in the summer, and he was joined in the starting 11 by Oscar, with Juan Mata and Eden Hazard rested.
Matchwinner at the weekend Frank Lampard continued alongside David Luiz in midfield, knowing a goal would bring him level with Kerry Dixon, second in the all-time Chelsea scoring charts.
Visitors QPR also made changes. Junior Hoilett came In for Djibril Cisse and Fabio in at full-back. Wright-Phillips dropped to the bench.
Marin’s first contribution was to pick up an early yellow card for a late tackle on Rangers’ Stephane Mbia, who would not be the last player in the wars in a fiercely contested opening period.
Hoilett was forced off after just 15 minutes, replaced by Wright-Phillips, while shortly afterwards David Luiz, who to that point had taken the game’s only meaningful effort, volleying narrowly over, clattered into his own team-mate Oscar inside the centre-circle, with the younger Brazilian requiring treatment from Chelsea medical staff.
Once recovered, Oscar shot wide from distance, while Marin bent over from the edge of the box as Chelsea looked the more threatening side, though without a real chance to speak of in the opening half-hour.
Oscar caught a decent sight of goal inside the area when Marin slipped him in, but his curling effort was deflected wide by the head of Clint Hill.
On rare forays out of their half, QPR had seen Wright-Phillips twice scuff wide with unlikely efforts, but were otherwise struggling to leave their half, the mercurial Adel Taarabt suffering near anonymity at the front of their formation.
Two minutes beforethe break, Julio Cesar was forced into his first save, knocking another deflected Oscar effort away with his feet, before seeing Victor Moses fire the follow-up over from 18 yards.
The game could not really have got any worse at half-time, but it picked up quickly and Chelsea almost took the lead three minutes after the break.
Marin twisted and turned his way in from the left and squared across a crowded penalty area, where Moses just failed to make a true enough connection to put his side in front.
Moments later Lampard was crowded out as he was about to pull the trigger, but you sensed an opening goal may not be far away, with corner after corner beginning to come our way. Ivanovic headed over, via the crossbar, from Marin’s centre and then Torres was denied at point-blank range by a flying Cesar.
QPR’s first effort on target came two minutes before the hour mark, when Esteban Granero, following intelligent build-up from Wright-Phillips and Taarabt, whipped an effort towards Turnbull’s far post. Alert and nimble, the goalkeeper was able to hold the well-struck shot.
Turnbull was quick off his line again, but needed the help of Gary Cahill to intervene after Taarabt’s deft backheel put Jamie Mackie in on goal, and then Shaun Derry sent a free header straight at the goalkeeper as his big night came to life.
On 66 minutes Chelsea thought the breakthrough had been made. Moses had seen his powerful drive deflected wide, and from the resultant corner, the ball fell loose to Lampard, who sent an unstoppable half-volley into the bottom corner. The linesman’s flag was already raised though, and the wait went on.
With Mata on for Moses, a goal seemed more likely than ever, and it came, but not where it was expected.
A QPR corner fell to Taarabt outside the Chelsea box, and another neat touch from him knocked the ball down to Wright-Phillips, whose low drive into the bottom corner would have beaten any goalkeeper. It was the best of the little winger, and quality all too rarely seen during his Stamford Bridge days. He did not celebrate the goal, his first in the league since May 2010, which set his side up for their first away win of the season.
Desperate for an equaliser, Chelsea piled forward, and it was Ivanovic who drew the foul from Hill 20 yards from goal. David Luiz took the shot, but it was straight into a densely-populated QPR wall.
A minute from time, the Serbian met Mata’s cross and it looked for all the world like a goal, but the ball flew just over the bar, consigning us to a first league defeat in a month, and the worst possible start to 2013.
Chelsea (4-2-3-1): Turnbull; Azpilicueta, Cahill, Ivanovic, Bertrand; David Luiz, Lampard (c); Moses (Mata 74), Oscar, Marin (Hazard 59); Torres
Unused subs Hilario,Ferreira, Cole, Ramires, Piazon.
Booked Marin 3
QPR (4-4-1-1): Julio Cesar; Onuoha, Nelsen, Hill (c), Fabio; Mackie, Derry, Mbia, Granero (Park 89); Taarabt (Dyer 90+1), Hoilett (Wright-Phillips 15).
Unused subs Green, Ferdinand, Faurlin, Cissé.
Goals Wright-Phillips 77
Referee Lee Mason