Ebere Eze scored both goals in a 2-0 victory for QPR over Preston, who dropped out of the Sky Bet Championship play-off places after a fourth straight defeat.
The win was Rangers' first in eight matches – and the clean sheet their first of the season.
Eze put them ahead after 17 minutes and doubled their lead with a penalty midway through the second half.
The opener came when Geoff Cameron opened up the Preston defence with a superb ball forward and Eze netted at the second attempt after his first effort was saved by keeper Declan Rudd.
Eze had plenty left to do after Rudd's stop but the England Under-21 international showed great composure to steer the ball past Preston's Ben Pearson.
Rangers continued to have the upper hand and could have extended their lead before the interval.
Marc Pugh's shot was saved by Rudd before Jordan Hugill, playing against his former club, fired over after being set up by Nahki Wells' knockdown.
Rudd was called into action again soon after the break, this time to save another shot from Eze.
With his team struggling to create chances, Preston boss Alex Neil sent on three attacking players – Billy Bodin, David Nugent and Josh Harrop – early in the second half.
However, his team fell further behind after 67 minutes when Eze tucked away the resulting spot-kick after Pugh had been tripped by Rudd.
The goals took Eze's tally for the season to nine and further enhanced the young forward's growing reputation. He was given a standing ovation by the home crowd when substituted with a couple of minutes remaining.
Preston, meanwhile, are struggling badly and have failed to score in all four of their consecutive losses.
They had been something of a bogey side for QPR, having won the previous six meetings between the two clubs.
But it was a different story this time and North End, who have scored just six away goals this season, rarely looked like mounting a comeback once Rangers had gone ahead.
They would have pulled a goal back late on but for a fine save from keeper Joe Lumley, who dived to push away Bodin's powerful strike and ensure his team's long wait for a shutout finally ended.
Rangers threatened late in the game as well, with Hugill shooting over and Grant Hall's cross just evading Cameron.
