Deane Smalley bagged both goals as Chesterfield stretched their lead at the League Two summit to six points with a 2-0 win at Gillingham.
Smalley, on loan from Oldham, struck in each half as the Spireites stretched their recent unbeaten streak to seven games.
Despite the hosts having the majority of possession, Chesterfield were happy to play on the break and took the lead with a well-worked goal on 13 minutes when Javan Vidal's cross was headed home by Smalley.
The Gills continued to press and the visitors had keeper Tommy Lee to thank for two smart stops from Cody McDonald within a matter of seconds.
Having soaked up the pressure, the Spireites doubled their advantage five minutes after the break and it was Smalley again, skipping round keeper Alan Julian and sliding home.
Gillingham stayed on the front foot, but both Luke Rooney and Adebayo Akinfenwa wasted late opportunities to cut the deficit.