Grimsby Town beat League One Doncaster Rovers in their first home pre-season friendly of the summer.
In a physical encounter, a single goal scored by Jake Hessenthaler with seven minutes to go proved enough to separate the sides.
Town boss Michael Jolley started with a strong XI, with James McKeown in goal behind a back four of Luke Hendrie, Ludvig Ohman, Mattie Pollock and Liam Gibson.
Harry Clifton, Hessenthaler and Elliott Whitehouse were the midfielders, with Moses Ogbu behind the strike partnership of James Hanson and Matt Green.
Doncaster named a bigger squad for the game, with last season's top scorer John Marquis among the starting line-up.
The visitors had the first chance of the game on seven minutes, with Kieran Sadlier turning and firing into the side-netting from the edge of the penalty area.
At the other end, a foul on Hanson brought a free kick in a central position but the ball into the box from Hessenthaler was headed clear.
A Witehouse cross from the left on 14 minutes found Hanson but his header was caught by keeper Ian Lawlor.
Marquis was booked for a late challenge on Hendrie and was then spoken to again by referee Geoff Eltringham shortly afterwards following a foul on Ohman.
Hendrie did well to challenge Madger Gomes and ensure only a corner after the winger looked to cut into the box from the right on 25 minutes. The flag-kick came to nothing.
Whitehouse then forced a good save from Lawlor with a low effort from 20 yards, before the resulting corner was headed over the bar by Pollock.
On his first appearance at Blundell Park, Whithouse was involved again on 34 minutes, bursting into the box from the left before sending over a low cross which was cleared.
A Doncaster corner soon afterwards was headed over the bar by Joe Wright, before McKeown was booked after racing out of his penalty area and catching Matty Blair. Ali Crawford's resulting free kick from the left curled wide of the far post.
One added minute was played at the end of the half and after an attempted lob by Marquis drifted harmlessly wide, the game remained goalles at the break.
No changes were made before the restart and the away side created the first opportunity of he second half, although Gibson was in the right place to clear a low shot by Ben Sheaf off the line.
Town made the first substitution of the game on 55 minutes, with Sebastian Ring rplacing Gibson at left-back.
A Mariners corner came soon afterwards but the ball was cleared by Marquis after Ohman's header.
A foul by Sheaf on Clifton gave Town a free kick midway inside the Doncaster half on 64 minutes but Hanson could not get on the end of Hessenthaler's ball.
Green saw a shot eflectd away for a corner three minutes later but the Mariners were unable to profit from the flag.
McKeown did well to make a stop after a cross from Reece James on the Doncaster left was deflected towards his goal, with the keeper diving to keep the ball out.
The visitors made four changes on 75 minutes, with Gomes, Sadlier, Marquis and Blair all making way for Alfie May, Will Longbottom, Max Watters and Alex Kiwomya.
Town then made changes of their own two minutes later as Ahkeem Rose and Jordan Cook replaced Hanson and Ogbu.
AJ Greaves replaced Crawford for Doncaster on 80 minutes as the visitors made a ffth substitution.
A Town corner on 82 minutes was cleared but the Mariners did not have to wait much longer to make their breakthrough, as a great effort by Rose crashed back off the bar before HESSENTHALER fired into the top corner from the edge of the box.
The Grimsby defence dealt with a Doncaster corner at the other end as heavy rain began to fall.
Max Wright came on in place of Green with four minutes to go, before Pollock was shown the yellow card for a foul in a central position, 25 yards from his own goal. The free kick went over the bar though and Town's lead remained intact.
Two added minutes were played at the end of the game before the Mariners' victory was confirmed.
They are next in action on Tuesday when they make the trip to face Scarborough Athletic, before Peterborough United visit Blundell Park on Saturday.