Jake Scrimshaw scored on his home debut after starting the game due to a Harry Bunn injury during the warm-up.
Four minutes in, the Iron had a brilliant effort go just wide after Myles Hippolyte's volley went over the goalkeeper's head but just skimmed past the post and out for a Sutton goal-kick.
Sutton almost took the lead when striker Omar Bugiel got in a good position, but his one-on-one shot was stopped after an outstanding save Rory Watson.
Bugiel had another chance to give the visitors the lead minutes later after he was left alone in space on the edge of the box and fired a low shot towards goal but was pulling away from the goal and out for a goal-kick.
Lewis Thompson received the first yellow card of the game after stopping a Sutton counter-attack from the previous corner.
Watson was called into action again after David Ajiboye played in attacker Donovan Wilson, whose shot across goal was easily saved by the shot-stopper.
Thompson had a great chance to put the home side ahead when Devarn Green crossed the ball into the box, with Thompson following from deep and hitting the ball at goal but his attempt was blocked by the Sutton defence and went out for a corner.
Sutton defender Ben Wyatt had to be treated by the medical staff after a cut had opened up on his head.
Moments before half-time, Sutton had an effort go wide again when captain Craig Eastmond hit the ball on the volley but the ball again went out for a goal-kick.
Six minutes into the second half, the Iron took the lead through debutant Scrimshaw after Sutton goalkeeper Dean Bouzanis misjudged Thompson's headed shot on goal, with the forward following up on the mistake and overhead kicking it into the net.
Minutes later, Scunthorpe almost doubled their lead after a headed effort from Emmanuel Onariase following a ball by Hippolyte from a corner.
Alfie Beestin's curled effort then just went wide after being given the ball by Scrimshaw in loads of space on the edge of the box.
Scunthorpe made their first change of the game 20 minutes into the second half with Harry Jessop replacing Green.
Alex Perry was the second Iron man into the referee’s pocket after giving away a free-kick.
Scrimshaw then received a yellow card after disagreeing with the referee’s decision.
Scunthorpe made their second change after Thompson was replaced by Mason O’Malley, and made their final change as they brought off Hippolyte and replaced him with Jai Rowe.
Five minutes from time, Sutton equalised after Donovan Wilson’s shot found it’s way into the Scunthorpe net.
In the dying seconds of the game, Sutton had a chance to get a late winner after captain Eastmond picked up the ball in the centre of the box and kicked the ball off balance, with the ball bouncing narrowly wide of the post and out for a goal kick.
IRON: Watson, Taft, Onariase, Green (Jessop, 70), Beestin, Hippolyte (Rowe, 87). Thompson (O’Malley, 82), Scrimshaw, Pugh, Davis, Perry.
IRON SUBS NOT USED: Collins, Wilson, Shrimpton.
SUTTON: Bouzanis, Barden, Goodlife, Rowe, Wyatt, Eastmond, Beautyman, Davis (Boldewijn, 69), Ajiboye (Korboa, 77), Wilson, Bugiel (Smith, 90).
SUTTON SUBS NOT USED: House, John, Kizzl, Bennett.
ATTENDANCE: 2,429.
