The Spireites came from behind to record their third Stadum MK win of the season in a stunning away performance, winning 2-1 at MK Dons.
The confidence back in Spireites boots, Gary Roberts levelled and, after Dons captain Dean Lewington had received a second yellow card, Caolan Lavery won the match with a late flick to send the travelling fans into ecstasy.
The Spireites starting line-up rang just a single change from Saturday's assured victory over Fleetwood Town. The injured Dan Jones stayed at home in Derbshire with Jay O'Shea taking his starting berth. The change meant Sam Clucas again reverted to the left back role he has fitted so comfortably into when called upon in recent months.
The home side enjoyed plenty of possession in the opening knockings, but the best chances of the early stages fell the Spireites' way. Good work from Roberts allowed O'Shea to drive in a shot from 19 yards, but it was blocked, and it was a similar case a few minutes later when great wing play from Tendayi Darikwa gave Ollie Banks space to shoot in the area, but again the effort was charged down.
A better chance still fell to Roberts eight yards out when O'Shea had a shot deflected after 15 minutes, it fell to the Spireites number 11 and his half-volleyed effort was well-struck but clattered back of Ian McLaughlin's near post and away to safety.
After Spireites number one Tommy Lee fisted away a dangerous Dons free kick, the Spireites went close again when a good Clucas cross found O'Shea at head height in the box. The Irishman could only get under his header however, and over the bar the ball went.
Despite the three good visiting chances, the Dons were the ones to take the lead just before the half hour. A corner found its way out to on-loan Chelsea man Baker, he steadied himself and slammed home a laser of a shot to give the hosts the advantage.
Now pushing for a leveller, Lavery nearly profitted from a defensive miscommunication as two MK defenders and the 'keeper left it for each other. Lavery was suddenly behind the defenders, but with a tight-angled open net to aim for the covering defender managed to block his goal-bound finish.
Sam Hird then found himself in an advanced position but blazed over when the ball was rolled across goal to him eight yards out by Banks.
Dons attacker Ben Reeves soon ran through after a Hird defensive mistake, he let fly from 20 yards, but his low shot was palmed away by Lee, with the players going in at the break seperated by that single Baker strike.
The second period started with Lavery again coming close to an opening for the Spireites. Played in by Roberts he tried to find space with a touch, but when his shot came in it was blocked behind for just a corner.
Will Grigg twice threatened a second for MK soon after, but while his first effort was blocked bravely by Ian Evatt, his second rolled some yards wide of Lee's goal.
With 66 minutes on the clock the Spireites fought themselves level and it was all down to Roberts. He played the ball through the legs of the last defender, ran onto it and finished snuggly inside McLoughlin's near post to make the scores square.
With events even and ten minutes left the Spireites were handed a further boost when Lewington was given his second yellow card. Both cautions were for fouls on substitute Gboly Ariyibi, who ran at the Dons skipper and forced the cautions.
A man down, the Dons had few intentions of throwing the towel, Carl Baker curling in a delicious strike that Lee had to be alert to and save.
The Spireites were pushing and in the last minute of the 90 the pressure took its toll when Lavery won the match with a crisp flicked finish from a deflected cross and Chesterfield completed their amazing seasonal Stadium MK hat-trick.
Subs not used: Burns, Green, Carruthers, Cole
Red card: Lewington 80'
Chesterfield: Lee (gk), Darikwa, Hird, Morsy (c), Ryan, O'Shea, Roberts (Dieseruvew 90'), Clucas, Lavery (Harrison 90'), Evatt, Banks (Ariyibi 62').
Subs not used: Chapman, Carter, Humphreys, Raglan
MK Dons: Price 28'