Paul Furlong scored a late winner to inflict a second successive defeat on league leaders Wigan.
An enjoyable match looked destined to finish goalless until the Rangers striker netted with 86 minutes on the clock to give his side a vital win in this top-of-the-table clash.
Furlong took full advantage of a superb breakaway and teasing cross from substitute Kevin McLeod, who robbed Jimmy Bullard in midfield before powering down the left.
His ball into the middle was met brilliantly by Furlong whose towering 16-yard header flashed into the net off the post with Wigan keeper John Filan helpless.
The sucker-punch was perhaps hard on the Latics who had been well on top, especially in the first 45 minutes, but they paid the price for wasting some glorious chances.
The visitors should have been 3-0 up at the break and will look back on those opportunities with massive regret.
First Jason Roberts put partner Nathan Ellington clean through on goal, but with just the keeper to beat he opted to pick his spot rather than go for power and Chris Day made the save look routine when he really should have been picking the ball out of the net.
Ellington then turned provider for Nicky Eaden on the right side of the penalty area as he quickly exploited a mistake in midfield by Rangers duo Marcus Bean and Matthew Rose.
But Eaden drilled his shot wide of the far post as Rangers were handed another reprieve.
And just a minute later, with the half-time whistle imminent, Bullard was denied by a brave save by Day as the midfielder attempted to skip past and convert into an empty net.
QPR came into it much more in the second half, but an enjoyable game looked destined to finish without any goals until McLeod's incisive counter-attack and Furlong's fine finish.