Goals in the final four minutes from George Milner and Dion Donohue saw the Spireites come from behind to beat Rotherham United 2-1 in the reserves.
The match saw returns from injury for Jake Beesley and Dion Donohue, while a team of mainly youth players lined-up against a similarly inexperienced Millers side.
The best chance in the early stages fell to to Spireites attacker Davis Keillor-Dunn but he put his shot wide when he may have expected to score.
The encounter developed into a tight if well-fought affair, with Chris Dawson going closest for United before the break when he drove a yard wide of Aaron Chapman's far post.
Things continued in a similar way after the break, though Dan Smalley really should gave scored when a deflected effort fell for him to head from six yards, but couldn't get his effort on target.
With 76 minutes on the watch, Rotherham were the ones to finally find the breakthrough. Substitute Fabien Bailey showed strength to muscle into the box and then composure as he slipped a shot under the oncoming Chapman.
Ten minutes later and with time running our Milner levelled the scores with a clinical header, and in the 89th minute the Spireites were given a golden chance to win the match after a scruffy challenge gave the hosts a penalty.
Donohue kept the coolest of heads to slot past former Spireites man Alex Cairns and the spot kick earned Chesterfield the points.
Chesterfield: Chapman (gk), Beesley, Daly, Marshall, Jarrald, Maguire, Greaves, Donohue, Simons, Milner, Keillor-Dunn
Subs: Morrison, Parkin (gk), Daswell, Hudson