It was an entertaining game and with the sides locked at 1-1 as the game moved into its final seconds Stags midfielder Stephen Dawson had a great chance to snatch all three points.
He was played clear in front of goal and seemed certain to score, but put his shot the wrong side of the post with just Mariners keeper Phil Barnes to beat.
However, a goal at that late stage would have been rough justice on the home side, who again came from behind on their own patch to pick up something.
A low-key first half was remembered chiefly for referee Ray Olivier being knocked over by a Mansfield clearance that caught him on the side of the head.
But there was much more action in the second half with the Stags sweeping ahead on 51 minutes.
A free-kick was not cleared and midfielder Matt Hamshaw drilled in a low shot for a second goal in successive games.
At this point Mansfield were on top and looking good for the three points, but Grimsby hit back with a strong spell during which they levelled in dramatic fashion.
With 72 minutes on the clock a good move involving Tom Newey and veteran winger Peter Beagrie saw the ball come across to the far post where 18-year-old Peter Bore met it with his head and the ball bounced down off the underside of the crossbar.
There were a few seconds hesitation before the referee signalled a goal and Bore appeared to injure himself in the celebrations, having to make way for Gary Harkins.
The action stepped up and the game could have gone either way with Grimsby bringing on giant defender Ben Futcher for striker Gary Jones and playing him up front.
The move could have conjured a winner for the Mariners, with Futcher getting up well and heading on, but Grimsby were unable to take advantage.