Chesterfield turned in a dazzling display with Jack Lester scoring a second hat-trick of the season as local rivals Rotherham were demolished 5-0 in front of a 10,000 plus crowd.
The visitors wilted as Dean Holden, Craig Davies and Lester gave the League Two leaders a 3-0 interval lead with Lester striking twice in the second half.
Chesterfield dominated from the first whistle and the only surprise was they had to wait until the 21st minute for the opening goal.
Dean Morgan latched onto a scuffed clearance and delivered a superb cross from the left which Holden converted with a diving header.
A wild back pass from Ryan Cresswell led to the 32nd minute corner that Deane Smalley flicked on for Davies to head in at the back post.
Andy Warrington kept the visitors in the game when he denied Lester minutes later but in first-half added time, the striker latched onto Danny Whitaker's pass and turned two defenders before curling a left-footed shot into the net.
Rotherham improved slightly but the night belonged to Chesterfield and Lester who punished poor defending in the 81st and 83rd minutes to complete the rout which sparked angry scenes from visiting fans.