A dour match failed to live up to the promise of a fast start as Chesterfield took the points at troubled Rotherham.
Home keeper Neil Cutler saved well from Caleb Folan after three minutes before Millers new boy Ian Henderson shot over and had a tap-in ruled out for offside.
Cutler was forced into another good save, this time denying Peter Holmes, before Folan fired in after being teed up by Paul Shaw after 33 minutes.
Rotherham never looked drawing level in a game dominated by Chesterfield.
Rotherham: Cutler, Worrell, Mills, Sharps, Brogan, Partridge (Newsham 53), Woods, Bopp (Robertson 45), Diagouraga, Facey, Henderson.
Subs Not Used: Montgomery, Cochrane, Wiseman.
Booked: Brogan.
Chesterfield: Jordan, Picken, Hazell, Downes, Davies, Smith (Hall 71), Niven, Allott, Holmes, Shaw, Folan.
Subs Not Used: Roche, Larkin, Nicholson, Kovacs.
Goals: Folan 33.
Att: 5,188
Ref: D Gallagher (Oxfordshire).