This time after dropping down in midweek they hit even more bitter county rivals Lincoln with an incredible four-goal burst in the last 13 minutes.
This will surely destroy any play-off aspirations of the Red Imps.
Hero in a fine team performance was recalled striker Adam Proudlock who hit a hat-trick, while his strike partner Jean-Louis Akpa-Akpro scored his first goals for the club to complete the rout.
Midway through the second half with Grimsby only leading 1-0, Lincoln threatened to make a game of it when they were awarded a penalty for hand ball against full-back Tom Newey.
Their best player Dany N'Guessan stepped up to make no mistake from the spot.
At that point the game really could have gone either way but it all changed on the 77th minute when Grimsby regained the lead.
Newey, who was in the thick of the action, went on an incredible one-man run but when the ball broke for Akpro he scored Grimsby's second to put them back in charge.
Then it all went wrong for Lincoln as they replaced defender Frank Sinclair with striker Adrian Patulea and they conceded three more goals.
Proudlock made it 3-1 on 82 minutes when set up by Danny Boshell, who repeated his set-up two minutes later for the fourth.
And then in added time, Akpro waltzed through on his own to hammer in the fifth.