Two-goal Gary Jones was one of the main Mariners heroes as he scored in both halves, but he was just shaded to the man-of-the-match honours by Grimsby full-back John McDermott.
The 37-year-old defender turned in a timeless performance, often being an extra attacker as he surged down the Grimsby right.
Town made the best possible start when a bright opening was capped by an ninth minute goal.
The impressive Ciaran Toner found left-back Gary Croft and, when his cross was nodded back by striker Tony Thorpe, Jones rifled it high into the net from close range.
The Mariners continued to be on top until they lost their way midway through the first half when they allowed Hereford back into the game.
Even so it seemed a harsh decision to award a penalty against defender Andy Butler, who was making his debut on loan from Scunthorpe. However, Rob Purdie was not one to look a gift horse in the mouth as he crashed his penalty high into the roof of the net.
It put the visitors level on 26 minutes and it was Hereford who looked the better side at this point but towards half-time Grimsby started to get back on top.
The second half mostly belonged to the hosts and they deservedly went ahead again on 61 minutes.
McDermott played a big part in the build-up with a fine long ball, and when Toner set up Jones he made no mistake with his second goal of the match from 12 yards.
Grimsby continued to boss the game and might have had further goals in the closing stages from Butler, Ricky Ravenhill and Jones although Hereford almost grabbed an equaliser when skipper Tamika Mkandawire headed just over from a free-kick.
It was a fast and open game which must have provided good entertainment for the television audience as well as the crowd of just over 4,100.