Sam Gallagher struck an injury-time winner as Rovers claimed a huge three points at Ewood Park.
The Rovers strike bagged his 11th goal of the season a minute into added time to clinch the victory for the home side.
It was the visitors with all the early chances, Jason Steele denying Jamie Mackie and Joel Lynch inside the opening three minutes, whilst Liam Feeney fired wide on the volley.
Rangers then thought they had opened the scoring just past the hour mark when Conor Washington's header bounced down off the crossbar, but the officials ruled that the ball hadn't crossed the line.
But the introduction of Connor Mahoney and Marvin Emnes turned the tied in Rovers' favour.
Darragh Lenihan saw a shot punched clear after an excellent free-kick from Mahoney, whilst Akpan and Gallagher both saw efforts go close as they pressed.
But as the clock ticked into time added on at the end of the match it was Rovers that would strike the devastating blow.
Feeney raced upfield before finding Emnes and he took the ball to the byline in the box before squaring for Gallagher to slam home from close-range.
The match was far from a classic, the victory all that matters.
Rovers made just the one change from the side that tasted defeat late on against Leeds United out as Craig Conway replaced Derrick Williams who missed out with a tight hamstring.
That meant a reshuffle at the back with captain Jason Lowe the man to move to the left back position.
But as the home side got to grips with their new formation, the visitors almost took full advantage from the opening whistle.
Just a minute into the match at Ewood Park a cross from Conor Washington dissected the Rovers defence, Jamie Mackie seeing his low shot saved by Jason Steele.
A minute later the two almost combined once more, this time Mackie inches away from connecting in front of goal.
As Rovers cleared the ball for a corner kick, Rangers threatened a third time in as many minutes. Joel Lynch seeing his header tipped over the bar by Steele.
Rovers regrouped and created an opening for themselves on nine minutes. A cross from Conway picked out Liam Feeney cutting in from the opposite flank, but on the half-volley he his shot flashed a yard wide.
After that flurry of early chances, play settled down with neither side gaining the upper hand. Aside from a Ryan Manning strike that flew wide and a header over from Sam Gallagher, there was little in the way of goalmouth action as the half ended scoreless.
After a slow start to the second half the visitors thought they had grabbed a 61st minute opener.
A cross from the right by Manning reached Washington at the back post, the striker directed his header goalwards only to see it bounce off the crossbar, down onto the line and into the arms of Steele.
The QPR players and visiting fans all celebrated the goal, but the linesman on the Jack Walker side ruled that the ball hadn't crossed the line. It looked a close call.
Both sides responded with substitutions. The Hoops brought on Matt Smith for Jamie Mackie, whilst Marvin Emnes and Connor Mahoney replaced Danny Graham and Craig Conway.
Within a minute an excellent Mahoney free-kick caused chaos as it flashed across the six-yard box, Darragh Lenihan saw his effort from a tight angle punched away, but Feeney couldn't get the rebound on target.
Play went straight up the other end with Smith nodding down for Washington, but the Northern Ireland international was wide with his shot on the turn.
Then a lovely touch run and pass from Mahoney set Gallagher racing goalwards, but excellent defending from Lynch prevented the Rovers man from getting his shot away.
Rovers kept pressing and probing in search of that elusive goal. Great work on the wing by Ryan Nyambe saw his centre come out to sub Hope Akpan, but his 20-yard strike fizzed narrowly over the bar. A minute later Gallagher tried an ambitious effort from a similar position, the ball finding the same supporters behind the goal.
But with Rovers pushing more men forward, they were vulnerable at the back. James Perch stinging the gloves of Steele with a swerving shot, before the Rovers keeper had to come out of his area to clear ahead of Washington.
The game was stretched and there for the taking, and thankfully it was Rovers who would finally strike in the 91st minute.
Feeney showed a quick pair of heels to race upfield before feeding Emnes and he tricked his way to the byline in the box before playing the perfect ball across the area to where Gallagher was there to gleefully fire under Alex Smithies and into the back of the net.
So often Rovers have been on the end of late goals this season, the fans delighted that for once it was they who were celebrating.
The manager and players had spoke in the week about getting the points rather than the performance, as the final whistle blew nobody cared about the game being far from a classic.
ROVERS: Steele, Nyambe, Greer (sub Akpan 70 mins), Lenihan, Lowe (c), Feeney, Bennett, Mulgrew, Conway (sub Mahoney 65 mins), Gallagher, Graham (sub Emnes 65 mins).
Subs not used: Raya (GK), Joao, Guthrie, Brown.
Goals: Gallagher 90+1 mins
QPR: Smithies, Bidwell, Onuoha (c), Lynch, Washington, Mackie (sub Smith 62 mins), Wszolek, Luongo (sub Morrison 78 mins), Perch, Furlong (sub LuaLua 90+4 mins, Manning.
Subs not used: Ingram (GK), Freeman, Hall, Goss.
Booked: Perch 59 mins, Manning 80 mins
Attendance: 10,846 (including 571 visiting supporters)