Chesterfield slumped further into the relegation doldrums after their 17th defeat of the season as they lost 1-0 to fellow strugglers Oldham Athletic.
The Spireites lost a real six-pointer down the bottom of the Sky Bet League One table against the ten-man Latics.
Anthony Gerrard saw red during the half-time break, leaving his side to battle for 45 minutes a man down.
After a resolute defensive display, all of the hosts’ hard work was undone at the Proact thanks to captain’s Peter Clarke’s stoppage-time header.
New boss Gary Caldwell named a much changed side from his first game in charge against AFC Wimbledon last time out.
Five changes were the cause of action thanks to a mixture of incomings and outgoings late on in the transfer window.
Daniel Jones, Tom Anderson, Sadiq El-Fitouri, Liam Grimshaw and David Faupala all started - with Liam O’Neil, Sam Hird, G’boly Ariyibi, Jay O’Shea and Rai Simons the quintet missing.
Three on those five were debutants in the form of El-Fitouri, Grimshaw and Faupala - whilst Ariyibi left on deadline day for Championship outfit Nottingham Forest, with O’Shea since joining Sheffield United on loan.
The Spireites were caught napping early on as seconds after the whistle went Ryan McLaughlin hit an effort just wide.
New boy Faupala had an early shot deflected for a corner as the hosts began to feel their way into the game.
The hosts held a lot of the ball without bursting through the Latics’ backline.
On the stroke of the half hour the Spireites had their best chance.
Welsh striker Ched Evans played wing-back El-Fitouri away, with Jones unable to sort his feet out to bury from close range.
Jon Nolan was then unable to find the back of the net after picking up the loose ball as his effort was blocked and then cleared.
As the players went in for half-time Gerrard received a second yellow card for an incident in the tunnel.
The already hard to break down visitors kept even more men behind the ball after the restart.
Jones whipped a ball across the face of goal on the hour, but no Spireites stud could get on the end of it to tap it home.
The hosts were almost caught on the counter by Aaron Amadi Holloway, with Dan Gardner covering well to avert the danger.
However, right at the death a well-earned point was snatched away from Caldwell’s men.
Clarke rose highest to head home past Ryan Fulton, with Oldham fans running onto the pitch after the ball went in.
Chesterfield: Fulton, El-Fitouri, Evatt, Anderson, Jones (Martinez, 65), Gardner, Grimshaw (Simons, 81), Nolan (Brown, 65), Donohue, Evans, Faupala.
Unused subs: Allinson, Maguire, Dennis, Mitchell.
Oldham: Ripley, Wilson, Gerrard, Clarke, Hunt, Flynn (Green, 45), O’Neill, Fane, Taylor (Obadeyi, 78), Holloway (Osei, 90+3), McLaughlin.
Unused subs: Ngoo, Law, Reckford, Banks.
Attendance: 6375 (883)
Referee: Ross Joyce (Cleveland)