Domingos Quina's second-half goal helped relegation-threatened Barnsley beat promotion-chasing QPR 1-0 and end a 13-game winless streak in the Championship.
Quina struck 16 minutes from time to move the bottom-placed Tykes five points from safety, giving boss Poya Asbaghi his first win in charge.
QPR striker Andre Gray fired in an early volley which was comfortably saved by Brad Collins.
Barnsley then enjoyed a decent spell with Carlton Morris having a long-range effort saved by David Marshall and Josh Benson putting a free-kick over.
Lee Wallace tested Collins with a firm, angled shot which was beaten away by the 'keeper at his near post.
Barnsley's Jordan Williams made a good run, beating several players before putting his effort over.
The hosts threatened again when Amine Bassi received the ball from Morris around 25 yards and fired in a shot which only just missed the target.
Benson then tried his luck from a similar position and Marshall saved comfortably.
With Barnsley enjoying plenty of possession, Claudio Gomes also fired in a shot from distance before the break with the ball clearing the bar.
Ilias Chair tried to beat Collins with an effort at his near post, but the 'keeper was equal to it.
Michal Helik made a vital block to thwart Gray inside the area, deflecting the striker's shot off-target.
Callum Styles dragged his effort wide after combining with Bassi.
Rangers boss Mark Warburton made a double substitution just after the hour-mark with Stefan Johansen and Charlie Austin coming on in place of Jeff Hendrick and Gray.
A third change was made five minutes later when Albert Adomah took over from Wallace.
After Gomes fired over, Barnsley made a change of their own when Romal Palmer replaced Benson.
Quina found the net with a left-footed drive which went in off the underside of the bar after Marshall got a hand to it.
The result put a dent in fourth-placed QPR's promotion hopes, ending a seven-match unbeaten run and leaving them six points off the automatic-promotion spots.
What the managers said...
Barnsley's Poya Asbaghi: "Of course you feel good after a victory. I think for us as well, with the results we have had this season, this win comes at a really good moment. It was a win that I felt was well deserved. I think we played well. In the first half, maybe we were a little too open and they were allowed to have too much on the ball. I felt that coming into the second half, we adjusted that pretty well. We were much more aggressive in our pressing in the second half.
"When I watched the second half, I honestly felt that we were the better team. It was a great goal from Dom that puts us in the lead and you never know how we're going to react, defending a lead because we haven't done that so much. I felt that the players did it in a mature way. It gives a lot for the confidence, I hope. The only way you can unite everybody in and around the club is to win football games and play good."
QPR's Mark Warburton: "It was a poor performance - as simple as that. You have to earn things out of games of football. We lacked fluidity in the first half and went in nil-nil. We knew what we had to do in the second half and, in truth, didn't do it. We're a team that creates chances and scores goals and today we weren't good enough. We didn't really hurt them.
"As a team, we didn't do enough. I was more than wary of Barnsley. They'd lost seven in a row and the law of averages tells you that they're due to win a game of football. That's fact. Unfortunately, we didn't really do enough to test their keeper. We didn't show the quality in the final third. We were nowhere near our best. I felt we were very laboured and slow against an opponent who are fighting for their lives."