Chesterfield, 2012 JPT winners and 2014 runners up, saw two of their rookies in an inexperienced 11 err in the first 25 minutes to allow Scunthorpe to take advantage with a 2-0 win
A third, Jack Broadhead, saw red for a second bookable offence on 84.
Charlie Raglan allowed Sean McAllister to convert whilst keeper Aaron Chapman, on as an early sub for Tommy Lee, slipped to allow ex-Spireite Gary McSheffrey to nick an easy one.
Paul Cook gave four players their first senior starts. Broadhead and Raglan were in the heart of the back line whilst ex-Owl Charlie Dawes and Gboly Ariyibi were on the wings. Ollie Banks started for the first time this season.
Scunthorpe put out a y strong side including former Wednesday man Miguel Llera, who was lucky to get only a yellow card for a forearm smash into flying winger Ariyibi, whose pace was a constant threat.
Chapman made a fantastic save to deny Paddy Madden and no doubt boost his confidence whilst Raglan almost made up for his slip with a decent header from a corner. Banks, Gnanduillet and Dawes all had solid efforts in an all action first half.
Spireites gave the match plenty after the break with Banks, who seemed to end the game carrying a knock, happy to shoot on site whilst Daniel Johnson and Dawes both went close.
Youth teamer Jake Beesley got a debut ahead of Broadhead’s dismissal and for the last few minutes, short handed Chesterfield threw everyone forwards to tray and earn some consolation, but none came their way.
Scunthorpe: Olejnik 6, Dawson 6, McAllister 8, Canavan 6, Madden 7 (Taylor 71), Bishop 7, Hawkridge 6, Adelakun 6, O’Neill 7 (Myrie-Williams HT, 6), McSheffrey 7 (Kee 71), Llera 6. Subs (not used): Weaver, Boyce.
Goals: McAllister 15, McSheffrey 25
Chesterfield: Lee (Chapman 6, 6), Darikwa 8, Broadhead 7, Raglan 6, Jones 6, Dawes 7 (Beesley 73), Ryan 6, Johnson 7, Ariyibi 7 (Onogwigun 73), Banks 6, Gnanduillet 6. Subs ( not used): Massey, Maguire.
Ref: Darren Handley (Lancs)
Bookings: Ryan (Chesterfield), Llera, Myrie-Williams, Taylor (Scunthorpe)
Sent-off: Broadhead (two yellows)