Nine wickets fell on a remarkable third morning at Wantage Road and the session ended with Northamptonshire on course for victory with Derbyshire 23 for 3 chasing 320 to win.
Northants resumed four wickets down with a lead of 289 and sights on setting a target towards 400. But such ambitions were destroyed as Conor McKerr took a second five-wicket haul in the game.
McKerr swung a full ball into the pads of Ben Duckett to trap him lbw for just 8 and took out the leg stump of Josh Cobb who recorded a pair. And when Rory Kleinveldt was cleaned up looking to runs with only the No. 11 for company, McKerr had 10 for 141 - the first ten-wicket haul for Derbyshire since Mark Footitt left the club.
It completed a quite remarkable Northants collapse from 225 for 1 yesterday afternoon. From four overs before the close on the second evening, Northants lost 8 for 33 in 18 overs.
It meant Derbyshire were right back in the game but still a testing 320 to chase. But 10 overs in and dreams of a first Championship win for two years were shattered as they lost three cheap wickets.
Billy Godleman miscued a pull that came off a top-edge to square leg, Jeevan Mendis was trapped lbw to an inswinger and Shiv Tahkor also fell pulling, his a full-blooded shot that was very well held by Cobb at square-leg. All three wickets were taken by Ben Sanderson.