Chesterfield's Shane Nicholson scored two penalties to condemn nine-man Huddersfield to defeat.
Nicholson tucked away his first when Tom Clark was red-carded for pushing Jamie McMaster in the 53rd minute.
McMaster was fouled again for Nicholson to make it two soon after but defender David McMirfin then headed Huddersfield back into the game.
But the visitors failed to find an equaliser and Efe Sodje was dismissed near the end for a second yellow card.
Chesterfield: Fulop, Bailey, Blatherwick, Evatt, Nicholson, Allott, Hudson (Allison 16), Niven, O'Hare, McMaster, De Bolla (Davies 87).
Subs Not Used: Richmond, Fowler, Logan.
Booked: Allison, Nicholson, McMaster.
Goals: Nicholson 53 pen, 78 pen.
Huddersfield: Rachubka, Mirfin, Tom Clarke, Nathan Clarke, Holdsworth (Abbott 66), Brandon, Ahmed, Carss, Collins (Efetobore Sodje 54), Booth, Facey.
Subs Not Used: Senior, Mendes, Schofield.
Sent Off: Tom Clarke (52), Efetobore Sodje (89).
Booked: Booth, Efetobore Sodje, Brandon.
Goals: Mirfin 79.
Ref: B Curson (Leicestershire).