Adam McGurk's brace sealed all three points for Burton Albion as League Two leaders Chesterfield lost their second home game in a row.
McGurk's first came from a low shot from 12 yards after 10 minutes and he headed his second minutes later from Chris Hussey's right-hand cross.
Robbie Weir should have made it three soon after but missed an open goal from close range.
Jay O'Shea's late shot was the closest the home side came to a consolation.
Chesterfield remain top of the table on goal difference while Burton climb to 12th and are now two point off the play-off places.
VIEWS FROM THE DRESSING ROOM
Burton Albion manager Gary Rowett told BBC Radio Derby:
"It's a very, very difficult place to come. Paul's produced a fantastic team, but we were magnificent today.
"I said before the game that I'd like to lose a game and say the opposition were much, much better than us, but I think again, we were absolutely fantastic.
"In truth, we could probably have won it by three or four. I know that might flatter us slightly, but we had some terrific chances and the game plan worked fantastically well.
"To come here and to do that, I thought was absolutely magnificent."
Chesterfield 01 Lee 25 Talbot (O'Shea - 46' ) 15 Humphreys 05 Morsy 04 Hird 06 Cooper 12 Ryan 07 Darikwa 24 Porter (Gnanduillet - 58' ) 17 Doyle 11 Roberts (Richards - 67' ) Substitutes 02 Banks 09 Richards 10 O'Shea 20 Chapman 21 Gnanduillet 23 Evatt 28 McSheffrey Burton Albion 01 Pickford 02 Edwards 07 Bell (Diamond - 77' ) 08 Weir (Dyer - 83' ) 06 Sharps 25 Cansdell-Sherriff 17 Phillips 23 Palmer 20 McGurk (Knowles - 86' ) 14 McCrory 03 Hussey Substitutes 05 Diamond 09 Howe 16 Lyness 18 Knowles 21 Holness 22 Dyer 28 Symes
Ref: David Webb