Lee Hendrie's first goal for Sheffield United eased the pressure on boss Bryan Robson as the Blades sealed their first league win in five matches.
Patrick Agyemang marked his first start for Rangers with a fine strike on the stroke of half-time.
But Damion Stewart's own goal handed United a lifeline in the 64th minute.
And Hendrie pounced five minutes later thanks to Billy Sharp's persistence on the edge of the box, which allowed the ex-Aston villa midfielder to fire home.
Sheffield United boss Bryan Robson:
"Everyone did a good job. The players showed a lot of character to come back in the second half.
"2007 was a bad year for the club but we turned a corner and we've got to take it from here. A top-six place is still the target.
"I've said before that the crowd has a big part to play and the supporters were magnificent."
QPR performance manager Joe Dunbar on Rangers' claim for a penalty:
"I've seen the video and it's fairly clear-cut. The ball was going into the top left-hand corner and Matthew Kilgallon turned it away with his hand.
"It was a classic game of two halves. We controlled the game in the first half.
"We feel disappointed to not be going away with a draw, which would have been a fair result."
Sheff Utd: Kenny, Bromby, Kilgallon, Armstrong, Geary (Gillespie 84), Carney, Hendrie (Stead 69), Speed, Tonge, Hulse, Sharp (Shelton 90).
Subs Not Used: Montgomery, Lucketti.
Goals: Stewart 64 og, Hendrie 69.
QPR: Camp, Barker (Blackstock 73), Connolly, Hall, Stewart, Mahon, Buzsaky, Rowlands, Lee, Agyemang, Vine.
Subs Not Used: Bolder, Ainsworth, Walton, Ephraim.
Goals: Agyemang 45.
Ref: Nigel Miller (Durham).