Ten man Oldham Athletic ended Chesterfield’s five match unbeaten league run at the Proact thanks to a Peter Clarke header in stoppage time.
Oldham’s Anthony Gerrard was sent off for a second bookable offence during the interval, but the Spireites were unable to capitalise on their extra man advantage.
Gary Caldwell handed debuts to three new players from the start and Dan Jones returned to the starting XI after a long spell injured.
Angel Martinez also returned from the bench in the second half but the positive feeling generated before the game turned into frustration as Chesterfield couldn’t break down Oldham, who in the end looked more like scoring when they went forward.
The game didn’t take long to explode into life, with Ryan McLaughlin firing an early shot just wide of the post after just ten seconds.
There was then a great break for the Spireites; Ched Evans cleverly let the ball run for Jones who crossed for debutant David Faupala whose effort was deflected over.
Five minutes later Faupala had another chance, this time provided by Jon Nolan, whose cut back found the Frenchman perfectly but his shot again went behind for a corner.
The Latics were looking dangerous going forward, particularly with Ryan Flynn on the right. His crosses were causing all sorts of problems, with Tom Anderson had to scramble the ball away from the line to deny a tap in.
The tempo of the game cooled after an end to end first 20 minutes.
On the half-hour mark Chesterfield had probably the best chance to take the lead. Sadiq El Fitouri’s fine cross found Jones with space just outside the six-yard box but he miss hit his shot. The ball then fell to Nolan who fired in but his shot was blocked.
After the half time whistle came the game’s talking point which saw Gerrard sent off for a second bookable offence.
The Spireites began on the front foot in the second half. Dan Gardner’s corner was headed over by Nolan and new signing Liam Grimshaw had a shot comfortably saved by Connor Ripley.
Chesterfield were having a lot of the ball, but Oldham sat back and frustrated the Spireites. A sequence of neat passing play saw Jones released by Dion Donohue but his low cross agonisingly missed everybody.
Despite the man advantage Gary Caldwell’s men were almost caught out. Aaron Amadi Holloway did brilliantly to hold off and then beat both Ian Evatt and Anderson but it was Gardner to the rescue as the midfielder nicked the ball off the striker before he could pull the trigger.
Many fans thought Faupala scored after Donohue crossed exquisitely from the left, but the on rushing striker tapped the ball into the side netting.
It almost got worse when Aiden O’Neill’s free-kick forced a fine save out of Ryan Fulton but the Spireites managed to clear.
After more Spireites frustration going forward, Oldham had a couple of corners and the second was turned in by Peter Clarke with a bullet header.
That came after the announcement of seven additional minutes, yet there were more stoppages as fans invaded the pitch after the goal and Amadi Holloway was treated for an injury.
In the end it was frustration for Chesterfield who travel to Northampton Town for their next Sky Bet League One fixture.
Chesterfield: Fulton, El Fitouri, Evatt (C), Anderson, Jones (Angel), Gardner, Nolan (Brown), Grimshaw (Simons), Donohue, Evans, Faupala
Subs not used: Allinson (gk), Mitchell, Dennis, Maguire
Oldham: Ripley, Wilson, Gerrard, O'Neill, Flynn (Green), Amadi Holloway (Osei), Taylor (Obadeyi), Hunt, Fane, Clarke (C), McLaughlin
Subs not used: Law, Reckford, Banks, Ngoo