Rotherham United produced a confident performance to condemn visitors Chesterfield to their first league defeat of the season and leap frog their local neighbours in the League 2 table.
Adam Le Fondre was the Millers' hero with the only goal of the game on 53 minutes but Rotherham also had goalkeeper Andy Warrington to thank for a string of second half saves.
Ronnie Moore made one change from last week's win at Barnet, with Tom Pope replacing Paul Warne.
The visitors started brightly and forced the first corner of the game on five minutes when Drew Talbot's dangerous cross from the right was headed out by Johnny Mullins.
However, it was Tom Newey who had the first shot of the game on seven minutes, but his ambitious long range effort was high and wide of Tommy Lee's goal.
The first effort on target came from Chesterfield after ten minutes, when Talbot headed Danny Whitaker's corner straight at Andy Warrington.
The Millers' top scorer Le Fondre almost had an opportunity on 12 minutes but Jason Taylor's pass was blocked by defender Dwayne Mattis.
Three minutes later Le Fondre volleyed over the cross bar after being picked out by Nicky Law's cross from the left.
The Millers were starting to get a decent foothold in the game and they missed the best opportunity of the game so far on 16 minutes. Good work by Kevin Ellison on the left created a chance for Danny Harrison but the midfielder couldn't connect properly and his header went harmlessly wide.
The home side continued to press and created another chance two minutes later but Le Fondre could only fire wide from Tom Pope's knock down.
The Millers continued to have the better share of play and worked the keeper again on 22 minutes, Law and Ellison worked a corner well and the latters delivery found Exodus Geohaghon in space but his header couldn't beat Lee in the Chesterfield goal.
A minute later the home side were almost in again but Mattis' last ditch tackle stopped Harrison from having a shot.
Rotherham continued to create the better chances and skipper Cresswell headed over Geohaghon's long throw.
A minute later, the visitors had keeper Lee to thank for stopping Taylor's rasping drive and the goalkeeper reacted well to stop Le Fondre getting on the end of the parried shot.
Ellison was next to try his luck for the home side on the half hour mark but he saw his goal bound effort blocked by Ford after neat interplay between Le Fondre, Law and Taylor.
The Millers continued to have the lions share of possession and Taylor blazed over after 33 minutes when he shot from distance.
Ten minutes before half time Jack Lester forced Warrington into a smart save after being put through on goal by Mark Allott.
Tom Pope brought the very best out of Tommy Lee on 40 minutes when his fierce, low shot from the edge of the area was expertly turned away low to the keepers left.
A minute before half-time and the visitors again had keeper Lee to thank for preventing the Millers taking the lead, this time doing well to stop Ryan Cresswell's close range header.
Chesterfield brought the half to a close by hitting the side netting. Striker Craig Davies easily beat Mullins inside the box but his shot with the outside of his foot didn't trouble Warrington.
Rotherham United 0-0 Chesterfield
The Millers took just four minutes of the second period to have their first chance. A Nicky Law corner resulted in a mad goal mouth scramble and Tommy Lee eventually saved from Cresswell.
However, it only took another two minutes for the visitors to have their first opening of the half but Craig Davies could only fire over from the edge of the box.
The Millers finally took a deserved lead eight minutes after the break when Adam Le Fondre brilliant lobbed Tommy Lee from just inside the area.
The striker was found in space from a Mullins throw-in and he looped the ball first time over Lee to the delight of the home support.
On the hour mark, the home side were a whisker away from doubling their advantage when Pope just failed to get on the end of a low cross from Newey.
A minute later Ellison tested Lee again but his curling shot was comfortable for the Spireites goalkeeper.
On 67 minutes, Pope was again inches away from getting on the end of a cross for the Millers, this time from a Law centre.
A minute later the visitors almost grabbed an equaliser but Warrington was equal to Dean Morgan's powerful drive, brilliantly parrying the winger's effort round the post.
On 75 minutes the Millers created another chance for Le Fondre. Excellent link up play between the impressive Tom Pope and Newey set up the striker but his shot was mis-hit and gathered by Tommy Lee.
Three minutes later Rotherham skipper Ryan Cresswell picked up the first booking of the game for a foul on Morgan and from the resulting free kick, the felled played forced another top draw save from Warrington.
The experienced keeper dove low to his left to keep out the low shot.
The away side piled on the pressure as the game went into the last minutes and the Millers were again grateful to Warrington for keeping them ahead. The stopper producing a superb double save to deny Niven and then the follow up from Davies.
The home side created a half chance for themselves on 83 minutes but Le Fondre couldn't get his shot on target from a tight angle.
Ronnie Moore made his first change of the game of 84 minutes, replacing Danny Harrison with Mark Bradley.
Rotherham United: Warrington; Mullins, Cresswell c, Geohaghon, Newey, Law, Harrison (Bradley 84), J. Taylor, Ellison, Pope, Le Fondre.
Subs not used: Fenton, Green, Warne, Marshall, Holden, Annerson.
Chesterfield: Lee, Hunt, Ford, Mattis c, Griffiths, Talbot, Whitaker, Allott (Niven H-T), Morgan, Davies, Lester (Gray 64).
Subs not used: Redmond, Boden, Breckin, Page, Clay
Words: Josey Webb