A second-half goal from substitute Mark Beck made it four wins from five at The Envirovent Stadium.
After a dominant opening 45 minutes the game looked to slipping away but a triple change with just over 20 minutes remaining provided the spark needed to grab victory.
Despite winning in midweek Simon Weaver opted to make three changes to his starting line-up; Ryan Fallowfield, Dan Jones and Lloyd Kerry coming in for Warren Burrell, Ed Francis and Josh Falkingham, who all dropped to the bench.
In Falkingham’s absence, George Thomson captained the side.
For the visitors, who gained a first win in midweek for new boss Paul Hurst, there were four changes with Luke Hendrie, Matty Pollock, James Hanson and Giles Coke coming into the side.
Such has been the change in the Mariners ranks in the January window that only three of the side who started the encounter earlier in the season at Blundell Park were named in the line-up this afternoon.
Town were looking to build on their recent impressive revival at home where they had taken 10 points from their previous five games. The restored Kerry was first to threaten the visitors goal with an early strike that went narrowly wide.
On 10 minutes Josh March’s snap shot was on target but dealt with comfortably by the on-loan Jake Eastwood.
A minute later March would again threaten, his volleyed effort forcing an excellent reflex save. March would also meet the resulting corner but his header failed to test Eastwood.
Town were pretty in possession and looking to get the ball wide early. A move involving both Kerry and March resulted in a teasing delivery from Simon Power that clipped the top of the bar.
With the end of the beckoning Aaron Martin also turned Town’s possession and territorial dominance into a meaningful lead but his near post header would only rebound off the base of the post.
However, the best chance of the half arguably fell to the Mariners, who had netted only 22 times during the campaign.
Thomson was dispossessed in midfield and a Grimsby breakaway saw Stefan Payne one on one with James Belshaw and the Town stopper was forced into a smart save to keep the game goalless at the half.
Town were unable to exert the same level of threat in the early stages of the second half though, with the Mariners five-man defence proving to be a tough nut to crack.
Josh McPake had one foray into the box when he got in behind his man but he had to settle to for a corner that was easily cleared by the visitors.
On 68 minutes and the game beginning to drift Weaver shook things up with a triple change. On came Jack Muldoon, Beck and Warren Burrell for March, Martin and the injured Jones.
The visitors also made the first switch with Lennell John-Lewis replacing Payne.
There began to be a greater sense of urgency about Town’s play; the introduction of Beck and Muldoon in particular giving the visitors defence a different set of problems.
It was Beck who ultimately did the damage when he rose to meet Fallowfield’s cross and arc his header to the far post with Eastwood finally beaten.
Weaver made a further change in the final 10 minutes with Falkingham replacing Kerry but it was the visitors, seeking to avoid a seventh successive away defeat, who almost snatched an equaliser when a loose ball fell to James Hanson but he blazed his shot well over the bar.
Substitute Morias then saw his goalbound effort deflected wide but Town stood firm to secure a second successive 1-0 win to move just four points from the playoff positions.
Harrogate Town: Belshaw, Fallowfield, Jones (Burrell, 68), Smith, Hall, Kerry (Falkingham, 81), Thomson, Power, McPake, Martin (Beck, 68), March (Muldoon, 68)
Subs not used: Minter, Francis.
Goal: Beck (77)
Grimsby Town: Eastwood, Hendrie, Waterfall, Coke, Hanson, Matete (Morias, 80), Hewitt, Pollock (Adams, 80), Menayese, El Mizouni, Payne (John-Lewis, 68).
Subs not used: McKeown, Rose, Green, Habergham, Adams.
Booked: Hewitt (16)
Referee: Trevor Kettle.