Sam Jones came off the bench to net from the penalty spot and earn Grimsby a 2-2 draw with Colchester.
Kyel Reid had twice put the visitors in front at Blundell Park, with JJ Hooper levelling the first time before Jones converted in the 89th minute.
It was Grimsby's first draw of the season, and United's first point on the road this term.
Colchester stunned Town inside five minutes as Reid set his sights from the edge of the box and beat James McKeown through a sea of bodies.
Town provided an instant response when Hooper latched on to a long ball from his skipper Nathan Clarke and smashed past Sam Walker.
Chances were few and far between as the minutes ticked by, but Reid doubled his tally for the night just before the hour.
Jones was then summoned from the bench, and the former Leeds trainee made his mark with a late penalty after Ryan Inniss fouled Jamille Matt.