But the club is due in court on Monday with the prospect of administration and a ten-point penalty that would destroy their promotion hopes.
Despite the looming disaster, the side claimed victory over their local rivals with two first-half goals from Peter Holmes and Marc Joseph.
Rotherham's dismal run, that had seen them beaten seven times in their previous ten outings, has led to them dropping out of the automatic promotion places.
Against their near rivals, Danny Harrison raced in on the Chesterfield keeper Barry Roche but he blocked well.
But the visitors flashed a warning when goal ace Jack Lester pounced on a long ball flicked on by Steve Fletcher but he smashed his effort over the top.
Holmes made a promising break down the left and hit an angled shot wide before Harrison's blistering shot was saved well by Roche at full stretch.
Jamie Ward shot wide for Chesterfield from 25 yards but then the home side broke the deadlock.
Youngster Jamie Yates was pushed down as he threatened just outside the area and Holmes curled a super free-kick around the wall and inside Roche's right-hand upright.
The home side could have added a second goal on 38 minutes when Yates swung in an accurate cross from the right but Chris O'Grady's glancing header was a fraction wide.
A minute before the break Rotherham doubled their lead with a stylish goal from defender Joseph. Holmes' free-kick was headed on by Graham Coughlan and the ball dropped kindly for Joseph who volleyed in.
Yates continued his impressive display when he cut in from the right but crashed over a long-range effort.
And only a sharp save from Roche denied the home side again when Mark Hudson's angled cross was headed down by Holmes before Roche beat it away.
Chesterfield struggled to find a way through and when substitute Jamie Winter saw a gap he fired over.
The visitors were given a lifeline 15 minutes from the end when Ward pounced on a loose ball and flashed in a left-foot shot but it was too little too late for the Spireites.