Russ Wilcox's Scunthorpe - who have not tasted defeat in the league since a 2-0 loss to Accrington Stanley in mid-November - appeared to be heading for a comfortable victory after establishing a 3-0 lead.
Sam Winnall opened the scoring in the 18th minute before two goals in five second-half minutes from Deon Burton and Paul Hayes.
Paul Cook's Chesterfield returned to the automatic promotion positions after coming from behind to beat Northampton Town 3-1 at Sixfields.
The league's bottom side went ahead after quarter of an hour through Darren Carter's penalty, but Danny Gardner levelled for Chesterfield on 25 minutes.
Burton Albion were leapfrogged in the table by Fleetwood Town, as the hosts' 10-match unbeaten league run came to an abrupt end in a 4-2 defeat at the Pirelli Stadium.
Burton twice came from behind thanks to own goals from Mark Roberts and Alex Marrow but Jon Parkin's strike gave Fleetwood a 3-2 lead and then Junior Brown rounded off the scoring in the fourth minute of injury time.
Elsewhere, Newport County's winless streak was extended to four matches, as goals from Kaid Mohamed, Eliot Richards and John-Joe O'Toole earned Bristol Rovers a 3-1 triumph, while Morecambe twice clawed back a deficit to draw 2-2 with Portsmouth.
York City's recent resurgence came to a halt as they lost 2-0 at Hartlepool United, with Manchester United loanee Jack Barmby scoring on his debut, while Plymouth Argyle needed an 84th-minute leveller from Luke Young in a 1-1 draw with Cheltenham Town.
