Danny Rose’s header handed Grimsby a 1-0 win and condemned AFC Wimbledon to their first league defeat at the Cherry Red Records Stadium this season.
Matty Stevens thought he had given the hosts the lead in the ninth minute after blasting the ball into an empty net.
However, referee Thomas Parsons called play back for a foul on Grimsby goalkeeper Jordan Wright in the build-up.
The Mariners went ahead against the run of play in the 30th minute.
Kieran Green produced an outrageous delivery with the outside of his boot to pick out Rose, who headed the ball past goalkeeper Owen Goodman.
James Tilley’s strike was tipped around the post in the 43rd minute as the Dons pushed for an equaliser.
However, Grimsby broke from the resulting corner and only some superb tracking back stopped Jason Dadi Svanthorsson from doubling the visitors’ lead.
Tilley had a long-range effort saved and Dadi Svanthorsson placed a shot just wide of the left post during a back-and-forth start to the second half.
The Dons maintained the pressure as Tilley dragged another left-footed attempt agonisingly wide of the Grimsby goal.
Wright was called into action yet again to deny Tilley with two minutes remaining and the visitors held on to secure the three points.
