The Spireites took the lead and had the chances to win but somehow fell to defeat as a late Dom Poleon goal defeated the Spireites 2-1 at Kingsmeadow.A Darius Charles own goal gave the Spireites a half time lead, though they were pegged-back by Paul Robinson's header before the hour mark.
The Spireites hit the post, created numerous openings, but Poleon's late strike decided the contest and sent the Spireites home pointless.
Back in league action, Danny Wilson made one change from last weekend's Millwall match, with Reece Mitchell - impressive from the bench against the Lions - getting a first Chesterfield start, with loan signings Tom Anderson and Conor Wilkinson starting on the bench.
An early chance came to Dons striker Lyle Taylor, after Ryan Fulton could only scuff a clearance into his path. A quick 30-yard shot came in, but Fulton was able to recover and catch the effort.
Captain Gary Liddle had a shot blocked after 'keeper Ryan Clarke could only punch away a corner, and Clarke was nearly embarrassed moments later when he misjudged a long ball, with Evans very nearly able to profit.
The Dons threatened with two corners, but after Taylor gave away possession on halfway Ched Evans turned quickly and shot towards goal, but dragged his effort a couple of yards wide.
On 30 minutes, Evans was closer still as he made room for himself in the area, fired towards the near post, with Clarke able to palm the fierce effort over the bar.
The Spireites made their pressure count on 35 minutes as after a direct run and cross from Mitchell won a corner. Hird rose in the centre for a header, with the final touch coming from Dons man Darius Charles.
Dons striker Taylor had a sharp effort deflected over the visitor's bar by Gary Liddle's late intervention, while livewire Mitchell came close to a second when he put Gboly Ariyibi's low cross just wide, the Spireites ahead at the interval.
The second period started with the Spireites looking to push on with their slender advantage, Evans being fed into space, cutting inside his man but slashing his low shot agonisingly wide.
Moments later Tyrone Barnett had a chance in the area, with the burly striker saw Fulton somehow manage to force his effort wide with a splendid save.
The Dons were level on 53 minutes, however. Robinson unmarked at the back post following a corner and getting just enough on his header to see it make its way into the top corner.
Taylor put a low volley into the side netting, before Jay O'Shea eeked out space but fired over from inside the box, both sides keen to register the contest's crucial third goal.
Substitute and debutant Conor Wilkinson came within a whisker of an immediate impact as he struck the post in the area, Ariyibi unable to convert the rebound.
Wilkinson was in the thick of the action again with 15 minutes remaining, setting his aim and firing marginally past the post from long range as the Spireites continued their assualt on the Wimbledon goal and a winner.
The Spireites were doing all they could to earn a winner, but a rare Dons counter saw Jake Reeves suddenly in space and bearing down on goal. The midfielder blinked too early however and fired over the bar.
Ariyibi soon saw his cross deflect into Wilkinson's path and the on-loan man flicked a boot out to send the ball goalwards, with Clarke able to show his reactions to save.
A winner did come, in the very last minute, but gut-wrenchingly it was the Dons who got it as Poleon finished neatly in the area with a low finish - the Spireites without enough time to claw anything back from the game.
AFC Wimbledon: Clarke (gk), Fuller (c), Robinson, Charles, Meades, Francomb, Reeves, Bulman, Barnett, Taylor (Elliott 72'), Barcham (Poleon 72')
Subs not used: Shea (gk), Nightingale, Whelpdale, Parrett, Kelly
Chesterfield: Fulton (gk) - Donohue, Hird, Evatt, McGinn - Mitchell (Wilkinson 65'), Liddle (c), Nolan (Anderson 85'), Ariyibi - O'Shea, Evans
Subs not used: Parkin (gk), Dennis, Gardner, Simons, Maguire
AFC Wimbledon: Robinson 53', Poleon 90'
Chesterfield: Charles (og) 35'
Attendance: 4,425 (406 away fans)