Jimmy Floyd Hasselbaink earned just his fourth win in 18 games as QPR boss as a below-par Derby were brushed aside.
Tjaronn Chery showed great technique to convert a 24th-minute James Perch cross for his third goal in his last five games for a deserved half-time lead.
The Rams had barely threatened but improved on the resumption and substitute Darren Bent forced a good save from keeper Alex Smithies.
But the hosts sealed victory late on through Gabriele Angella’s strike.
Angella slid in a teasing Matt Phillips free-kick to wrap up a win which takes Rangers up to 11th in the Championship table, nine points adrift of the play-off places.
Derby, seeking a fourth win in five, were outplayed in the first half by a home side who looked lively in attack thanks to the twin threat posed by wingers Phillips and Junior Hoilett.
Sebastian Polter went close before Chery’s fine finish following a superb run and cross by Perch on the left and Phillips almost got on the end of a Hoilett centre to double the lead,
Derby, who remain fifth, upped the urgency and adopted a more direct approach, but still struggled to create clear chances and defender Angella made it 2-0 with four minutes left.
QPR head coach Jimmy Floyd Hasselbaink: “I think we played ever so well from minute one until the last minute of the game.
“In the first half we dominated with and without the ball and scored a really magnificent goal.
“We could have done better on the break but that’s me being a little bit picky. Overall it was a great team performance.”
Derby head coach Darren Wassall: “I’ve been in charge for six games and we’ve won three and lost three, so anybody can see we need more consistency.
“It’s something we have to address. There are 10 games to go this season and we have to put it right.
“We’ve missed an opportunity to get at least a point. It’s bitterly disappointing. We’re taking two steps forward and one back.”