Jordan Maguire-Drew’s winner means the Mariners return 11 month after the heartbreak of relegation.
They came from behind to do it to the delight of 15,000 travelling fans.
But just seconds before the half-time whistle, Kyle Hudlin nodded Neal Ardley’s team in front.
On the 69th minutes it was one of Grimsby’s reliable marksmen who pounced - John McAtee’s composed low drive put Town on terms.
It took extra time to get the job done.
Substitute Maguire-Drew was alert to poke home at the back post to return Grimsby Town to the Football League.
Paul Hurst knows many owners would have fired the gun following relegation.
But he has rewarded their faith by delivering promotion - even if they needed three lots of extra time to do it!
“We like to provide a bit of value for money!” he joked.
"The owners here showed faith and I hope I've paid that back.
“They look at it in more objective terms and I am really pleased for them, of course I am - some maybe wouldn’t have.
“This is an amazing feeling, I'm so pleased for everyone.
“It’s been a huge effort and the way the players have handled the pressure is fantastic.”
PHOTO GRAHAM SCAMBLER