Paddy Madden found the back of the net twice, but the pick of the goals was a stunning 25-yard strike from Gary McSheffrey.
The same eleven took to the field for the fourth game running. Luke Daniels started in goal, and in front of him was a back four of Scott Wiseman, David Mirfin, Murray Wallace and Scott Laird. Neal Bishop once more played alongside Jack King in the midfield, with Madden, Tommy Rowe and McSheffrey playing in behind Tom Hopper.
Both sides started the game in a positive fashion, but it was the hosts who had the first effort on goal, inside of ten minutes. Sylvan Ebanks-Blake found some space on the edge of the penalty area and then attempted to chip Daniels. However, the United goalkeeper comfortably gathered.
15 minutes in, Hopper had the Iron's first shot. After outwitting his man, the attacker fired a low strike which stung the palms of Spireites shotstopper Tommy Lee.
Soon after, Madden tested Lee with a close range effort. The Irishman found himself free at the back post, but despite having time and space, he could only steer McSheffrey's free-kick into the arms of the hosts' 'keeper.
McSheffrey almost put the Iron ahead himself in the 22nd minute. The former Chesterfield man, like Madden before him, found room at the back post, but he couldn't direct his header on target.
The visitors were on top, and McSheffrey was the man who almost broke the deadlock on the half an hour mark, with a low strike from the left corner of the penalty area. It looked as though the ball would find its way into the bottom corner, but Lee showed sharp reactions to palm the effort away.
There was a warning for Mark Robins' men shortly after though, when Jay O'Shea hit a venomous shot from around 30 yards. Daniels could only watch as the ball arrowed towards the top corner. Fortunately enough, the strike was too high and rose over Daniels' crossbar.
Despite the warning, United continued to apply the pressure and were only prevented from the taking the lead due to some heroics from Lee in the Chesterfield goal. He firstly saved from McSheffrey and then brilliantly denied Hopper as he followed up.
Those heroics were to be the last action of a first half which the Iron dominated throughout.
Ten minutes into the second half United stamped their authority on the match. McSheffrey was sent tumbling to the ground by a challenge in the penalty area from Dan Jones. That left referee Darren England with no choice but to point to the spot and dismiss the Chesterfield full-back.
From the resulting spot-kick, Madden stepped up and sent Lee the wrong way, placing the ball into the bottom right hand corner.
The away support had only just finished celebrating Madden's goal, when they were treated to a moment of brilliance from McSheffrey. The ball sat up nicely for the winger, who then volleyed home spectacularly from all of 25 yards, leaving Lee with no chance.
After doubling their lead, United then went about looking for a third. Firstly, Hopper was denied after hitting a left-footed volley from just inside the area and then Lee was tested again, as Wallace headed goalwards from a corner.
In spite of their numerical disadvantage, the hosts continued to try and get back into the game. And they almost did when O'Shea rattled the crossbar, with a close range free-kick.
Robins' side added some gloss to the scoreline with ten minutes remaining, when Madden got his second. After being picked out by Laird, the Iron number 9 fired the ball past Lee, who looked to have been deceived by a bobble.
United had opportunities to add a fourth, but ultimately had to settle for three, on a fantastic afternoon for Robins and his side.
Chesterfield: Lee, Herd (O'Neil 87), Jones, Morsy (Ariyibi 87), Hird, Gardner, Ebanks-Blake (Simons 69), O'Shea, Novak, Raglan, Talbot.
Substitutes not used: Cairns, Banks, Dieseruvwe, Humphreys.
Scunthorpe United: Daniels, Wiseman (Clarke 58), Mirfin, Wallace, Laird, Bishop, King, Madden, Rowe, McSheffrey (Williams 71), Hopper (Lolley 81).
Substitutes not used: Anyon, Henderson, van Veen, McAllister.
Attendance: 6,340 (635 away).
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