Derby survived a late Crystal Palace fightback to keep alive their play-off hopes after a Pride Park thriller.
They raced into a 2-0 interval lead via Steven Davies and Jeff Hendrick goals.
Theo Robinson's penalty after Anthony Gardner handled a cross by Gareth Roberts made it 3-0 before Palace scored twice in the final 11 minutes.
Chris Martin and Darren Ambrose found the net for the Londoners, but Derby held on and are five points from the play-offs with seven games left.
Nigel Clough's side have certainly hit form at the right time.
Their fourth win in six games ended Palace's 10-game unbeaten league run.
Davies put Derby in front after six minutes, beating Julian Speroni with a rising shot from close range after linking up with Robinson.
Former Huddersfield player Robinson rattled the crossbar with a 20-yard attempt before Hendrick doubled the lead with a low shot into the bottom right-hand corner from the edge of the box.
It looked all over when Gardner handled a cross by Roberts, allowing Robinson to score from the spot - before Palace produced a spirited comeback.
Martin's goal in the 79th minute, a low right-foot shot from 12 yards, injected some urgency into his side's efforts.
Ambrose then set up a frantic finish when his 18-yard effort made it 3-2 with a minute remaining but Derby hung on to claim the points.