Coventry started the game with a seven match unbeaten run but it was the Iron who grabbed the three points, with the visitors playing the majority of the game with ten men.
Russ Wilcox made two changes from the side that started the Chesterfield fixture, with Lyle Taylor and Terry Hawkridge coming in for Hakeeb Adelakun and Andy Dawson.
Within the first minute, former Sky Blues midfielder Gary McSheffrey found space in the penalty area only to see his powerful strike parried over the bar by Allsop. The momentum was immediately with Scunthorpe as O’Neill almost found McAllister with a long, curling cross from deep, only for Allsop to intervene once again.
Frank Nouble almost split open the Iron defence after a great touch opened up some space for the Ipswich loanee, however, Canavan was able to intercept cleverly. Lyle Taylor also displayed his strength, holding off Willis before back-heeling it to McSheffrey who almost found Hawkridge unmarked in the box.
Within the opening ten minutes the claret and blue had already created multiple crossing opportunities, while Madden was able to turn his man and fire wide of the goal.
However, despite Scunthorpe dominating it was Coventry that took the lead with what was their first effort on goal. On the fifteen minute mark Simeon Jackson was able to squeeze a pass through the Iron back line and Nouble calmly slipped the ball underneath Olejnik.
Shortly after the deadlock was broken the Iron had Miguel Llera to thank for preventing the visitors doubling their lead, throwing himself bravely at Nouble’s powerful effort.
With twenty minutes to play before the interval Reda Johnson was sent off for an off the ball incident with Lyle Taylor. The defender appeared to move his head towards the Iron striker and the referee showed the centre back the red card. With the subsequent free-kick Paddy Madden had the ball in the back of the net, only for the linesman to flag for offside.
After a patient build up Sparrow was able to lay the ball off to McAllister whose shot fizzed over the bar. The Iron continued to dominate possession but could not find an opening to really test the Sky Blues shotstopper.
This all changed when McSheffrey found the in-form Paddy Madden on the penalty spot. McSheffrey volleyed the ball across to the Irishman, who finished in style, side-footing it into the far corner, sending the home fans into raptures.
Coventry replied with a counter-attack which ended in Olejnik denying a speculative 30-yard effort from Fleck. With ten minutes until the break the game was level and Scunthorpe continued to look the better side.
McSheffrey, who was captain for the evening, was involved in most of the Iron’s attacks and almost put his side ahead. Hawkridge spotted him on the edge of the area but the winger could not find the target with his strike. This was the final act of what was a very promising first 45 for the home side.
The Iron continued to use their numerical advantage over the visitors in the second half, creating a chance for Madden, only for substitute Hines to intercept O’Neill’s delivery.
Coventry almost found an opening for themselves when Hines whipped in a set piece to Clarke at the back post, but he struggled to get a clean connection on the cross.
Substitute Adelakun ended a flowing Scunthorpe move with a powerful strike at goal which was palmed wide by Allsop. The resulting corner was almost met by Llera at the back post, who would have had an open net to aim for had he found a connection.
The home side continued to push for a winner and with half an hour left on the clock Lyle Taylor was able to nod the ball into the roof of the net after being found in the middle by Paddy Madden. Scunthorpe had deservedly pulled it back from being 1-0 down early in the first half.
Williams dinked a ball into the middle on the 74th minute and Adelakun cleverly cut inside with a deft touch in the six-yard box, however, the Coventry back four were able to clear their lines with some last minute defending.
Scunthorpe remained comfortable in the lead and did not look like conceding, yet O’Brien almost found an equaliser for the Sky Blues with one minute left to play. He found some space in the home side’s penalty area but his low strike curled wide of the mark.
The Iron had to endure a nervy five minutes of injury time, including a couple of set pieces in which Coventry keeper Allsop came up for. In spite of this Scunthorpe were able to hold on for a valiant, well deserved victory; their third on the trot at Glanford Park.
Scunthorpe United: Olejnik, O’Neill, Llera, Canavan, Williams, Hawkridge (Adelakun, 55), Sparrow, McAllister, McSheffrey (Myrie-Williams, 81), Madden, Taylor (Kee, 87).
Coventry City: Allsop, Willis, Webster (Miller, 72), Johnson, Thomas, Fleck, O’Brien, Jackson (Hines, 41), Nouble, Clarke, Haynes.
Attendance: 2,866 (379 away fans)