The Premier League's bottom side claimed a remarkable victory on Wednesday evening, as QPR held on to defeat Chelsea 1-0 at Stamford Bridge.
Shaun Wright-Phillips - a former Blues player - scored the winner for Harry Redknapp's side, lashing home with barely 10 minutes remaining to clinch a remarkable victory that punctured any fleeting hopes Rafa Benitez's side had of getting back into the title race.
Elsewhere, Liverpool celebrated the signing of Daniel Sturridge with a comfortable victory over Sunderland, while Newcastle - without forward Demba Ba - were overhauled by Everton in a disappointing home defeat.
Chelsea's four-match winning run in the Premier League ground to a spectacular halt as struggling west London rivals QPR claimed their first victory at Stamford Bridge for two decades.
Shaun Wright-Phillips, an early substitute for the injured Junior Hoilett, struck a brilliant 78th-minute winner against the club he left in 2008 to further erode the Blues' fading title hopes. The club remain 14 points behind leaders Manchester United.
Wright-Phillips' second goal of the season topped a fine performance from QPR that was a vast improvement on Sunday's tame home surrender to Liverpool.
Rangers defended resolutely throughout and created more chances to score in an entertaining second half, as Adel Taarabt ultimately laid the ball off perfectly for Wright-Phillips to drive home.
It was a crucial victory that ended their three-match losing run, giving Harry Redknapp his second win since becoming manager last month, and while they remain bottom of the table on goal difference the result invigorated their relegation battle.
Liverpool may have brought in reinforcements to ease the apparent burden on striker Luis Suarez, but their leading scorer appeared not to notice as he hit two as the Reds beat Sunderland 3-0 at Anfield.
The Uruguay international took his tally to 15 in 19 league matches - the last Reds player to reach that total was Fernando Torres in 2009-10, scoring 18 a year after they almost won the title.
Raheem Sterling opened proceedings with a well-taken lob over goalkeeper Simon Mignolet, as Liverpool began the new year with a home victory after recording just six in the league in the whole of 2012.
But it was polished off by Suarez, who hit two right-footed efforts - both assisted by Steven Gerrard - past Mignolet either side of half-time to give Brendan Rodgers' men a comfortable win.
In the night's other game, Newcastle were beaten 2-1 by Everton as the Toffees improved their own Champions League aspirations.
The Magpies, without Demba Ba as the striker prepares to complete his move to Chelsea, did not immediately miss the Senegalese international - especially when compatriot Papiss Cisse showed great wherewithal to head the opener over Tim Howard after just two minutes.
But Everton soon clambered back into the match - getting on level terms shortly before half-time as Leighton Baines rifled a wicked free-kick beyond the utterly deceived Tim Krul.
And the winner came with 20 minutes remaining; Victor Anichebe on hand to prod home after great work from Nikica Jelavic down the left. Newcastle had their chances to equaliser in the closing stages - Cisse and Davide Santon both seeing great openings - but Howard held firm as David Moyes' side moved within two points of Chelsea in fourth.