The Spireites came from behind to secure their first win of the season. Matt Smith gave Oldham the lead midway through the first-half but Danny Whitaker levelled early in the second-half and Smith’s own goal at the death sent Chesterfield through the second round of the competition they of course won last season.
The visitors had a great chance to score in the opening couple of minutes when Robbie Smith headed down to Christian Montano who shot from a good position.
Scott Boden put a header narrowly wide for the Spireites before a good spell for Oldham, during which Smith gave them the lead.
Simpson had a shot deflected wide while Smith put a low, angled shot beyond the far post and Lee Croft had an effort blocked.
The breakthrough for Oldham came in the 23rd minute when Smith beat Tommy Lee with a far post header after meeting Croft’s right-wing cross.
Marc Richards threatened at the other end following a defensive mix-up but he dallied and the chance was gone. The attempted clearance went straight to Mark Randall who fired well over.
Chesterfield finished the half strongly with Neal Trotman heading wide from Sam Togwell’s long throw and Drew Talbot firing off-target from the right-hand side of the area.
Whitaker equalised three minutes after the re-start, when Carl Winchester’s attempted header back to Dean Bouzanis failed to reach the keeper. Whitaker seized on the loose ball and ran through the middle before slotting past Bouzanis.
The Spireites put Oldham under pressure with Randall side-footing wide after Talbot capitalised on a defensive slip and Bouzanis beating away Whitaker’s 20-yard effort.
Whitaker was presented with a chance to score his second goal of the night in the 62nd minute when a penalty was awarded following Jonathan Grounds’ foul on Richards in the area. But Whitaker’s spot-kick was saved by Bouzanis, diving to his right.
Whitaker then had a low shot saved as he looked to atone for his penalty miss.
Oldham substitute David Mellor put a low shot wide and Lee kept out a long-range strike from Youssouf M’Changama.
Lee was beaten by another effort from distance when Connor Hughes tried his luck, but the bar came to the keeper’s rescue.
Lee had to go off shortly afterwards after falling awkwardly when attempting to claim the ball. Summer signing Richard O’Donnell took over in goal.
The winner came in stoppage time when Smith appeared to get the final touch to turn the ball into his own goal following a right-wing cross from Talbot.
Chesterfield: Lee (O’Donnell 89), Forbes, Trotman, Hird, Ridehalgh, Talbot, Togwell, Randall (Clay 90), Whitaker, Boden (Hazel 65), Richards
Subs not used: Darikwa, Lester, Clay
Oldham: Bouzanis, Grounds, M’Voto, Tarkowski, Winchester (Mellor 71), Byrne, M’Changama, Croft (Millar 71), Simpson (Hughes 65), Montano, Smith
Subs not used: Cisak, Taylor