Sam Cosgrove scored twice as Plymouth came from two goals down to beat Derby 3-2 at Pride Park.
James Collins and Nathaniel Mendez-Laing put Derby in control but former Rams striker Morgan Whittaker and Cosgrove turned the game around.
Derby scored in the 26th minute when David McGoldrick robbed Brendan Galloway and set up Collins who slid the ball in from 10 yards.
The visitors should have equalised seven minutes later but Joe Edwards shot was blocked on the line by Jason Knight.
Derby scored again in the 38th minute when Mendez-Laing turned brilliantly away from two defenders to drive in his third of the season.
Plymouth hit back in the 56th minute when Whittaker pounced from close range after Matt Butcher's shot was blocked.
Derby were giving the ball away and they were punished in the 77th minute when Niall Ennis's sliced shot was turned in by Cosgrove.
The comeback was completed in the 90th minute when Cosgrove broke clear on the right and squeezed the ball in from a tight angle.