Doncaster Rovers 1 Grimsby Town 0: Joe Ironside penalty secures three points for Grant McCann's men
Ironside smashed home from the spot on 72 minutes after substitute Kyle Hurst was brought down by Gavan Holohan.
There had been little between the two sides for the majority of the contest, with both struggling for sustained possession.
Harry Clifton headed over the bar from a great position as Grimsby started the brighter.
Ironside was picked out by Tom Nixon in an excellent position but fired over before Doncaster keeper Louis Jones made an excellent save to keep out Holohan’s low drive.
Danny Rose struck the inside of the post early in the second half for Grimsby while Ironside flicked a header wide from a Jack Senior cross.
After Ironside gave Rovers the lead, 18 minutes from time, it was Doncaster who had the better of the opportunities.
Hurst drilled into the sidenetting at the end of a breakaway while Owen Bailey rattled the bar with a first-time effort from a corner.