After taking the lead slightly against the run of play with Derek Niven’s first goal for the club on 13 minutes, Town never looked in any danger and they doubled their advantage through Nathan Pond seven minutes later.
Grimsby caused plenty of problems for their visitors throughout the evening, with the pace and trickery of Scott Neilson and Joe Colbeck on the wings proving to be a constant threat.
And the home side made the points safe after the break, when loanee Ross Hannah grabbed his second goal in two games since his move from Bradford City.
Town joint managers Rob Scott and Paul Hurst named an unchanged starting XI after the convincing 4-1 victory over Luton last time out.
That meant James McKeown started in goal, with Bradley Wood, Shaun Pearson, Pond and Aswad Thomas making up the back four.
Colbeck began on the right wing, with Craig Disley and Derek Niven continuing as the central midfield pairing and Neilson lining up on the left.
Hannah and Andy Cook were again named as the preferred partnership in attack, while the substitutes bench also remained unchanged, with Sam Hatton, Ian Miller, Anthony Elding, Frankie Artus and Dayle Southwell all waiting in reserve.
Gateshead travelled down from the north-east looking to improve on their mid-table placing, with ex-Town midfielder Micky Cummins among their starting line-up.
Another threat to the Grimsby backline was likely to come from striker Yemi Odubade, who was partnered up front by Ryan Donaldson.
Town kicked off attacking the Osmond Stand end of the ground and were immediately on the attack, with a cross from Wood on the right looping over visiting keeper Adam Bartlett but bouncing just past his far post.
Disley was penalised for a foul on the edge of his own penalty area on five minutes but the resulting free kick from the right was headed clear by Pond.
Another foul, this time by Wood, gave the away side a chance to get the ball into the box again and this time, it was headed behind for a corner, which Disley dealt with.
At the other end, a ball from Neilson ricocheted off a Gateshead defender and was eventually played to Colbeck, who forced Town’s first corner on the 10-minute mark.
Centre-back James Curtis had to receive treatment on an injury before the corner was taken and from the flag, the Mariners took the lead.
Colbeck’s delivery was headed against the bar by Pond and NIVEN was there to stab the rebound home from 10 yards.
The goal had come against the run of play, with Gateshead having most of the early possession but Town had made their first real chance count.
After taking the lead, the hosts took control of the game, keeping the ball well and looking to build up attacks.
A free kick for a foul on Thomas near the left corner flag gave Colbeck another chance to get the ball into the danger zone and again, it led to a goal.
The winger crossed to the far post and POND was there to meet it and double the Grimsby advantage with less than 20 minutes on the clock.
The away side had a good opportunity to pull a goal back on 24 minutes when a foul by Wood gave them a free kick on the edge of the Town penalty area but the shot could only hit the Grimsby wall.
Another free kick, this time leading to a booking for Neilson for a foul on Curtis resulted in McKeown coming off his line to comfortably claim the ball from Paddy Boyle’s delivery.
Neilson won a corner on the Mariners left on the half-hour and Colbeck’s ball was headed behind for another one by defender Carl Magnay, although the winger’s second delivery was too strong and was eventually cleared after Niven had picked it up on the left.
Town kept control of possession as Gateshead struggled to make any impact on the game and Disley was the next to go close, curling a shot just wide of the far post from 25 yards.
The pace of Colbeck and Neilson was causing plenty of problems for Gateshead and Colbeck won another corner on the right on 36 minutes. They could not make it count though, as Cook was penalised for a push as the ball came over from the flag.
Another attack from the dominant hosts saw Hannah cross from the right for strike partner Cook but the ex-barrow forward could not get a strong connection on his header and the ball dropped well wide.
Gateshead then had a spell with the ball and used a neat, passing style to build up an attack that eventually brought a free kick in a central position, 25 yards from goal. Striker Odubade took it but could only hit the Town wall.
Niven was shown a yellow card for a foul on Cummins after Gateshead looked to break quickly when Thomas lost the ball on halfway.
Josh Gillies took the free kick and this time, got it up and over the wall but the ball also cleared McKeown’s crossbar.
Two added minutes were played at the end of the half and with no further chances for either team, the hosts’ two-goal advantage remained intact at the interval.
No changes were made by either management team before the restart and Grimsby almost added a third goal four minutes into the second half when a long throw from Wood was headed on by Pearson but the ball bounced off the bar.
Two corners in quick succession allowed Town to keep the pressure up but keeper Bartlett was not called into action as the second one was headed across goal by Pond before being hacked clear.
Gateshead almost halved the deficit when a low cross from Odubade was missed by McKeown but Cummins could not get a boot to the loose ball on the six-yard line and the chance was gone.
At the other end, Disley picked up a pass from Niven and turned his man before letting fly from 25 yards, although Bartlett got down to make the stop.
Neilson and Colbeck linked up well down the right on 54 minutes but the latter’s cross was headed away by Curtis.
Gateshead were playing with much more urgency after half-time and another low ball across the Town six-yard box from Gillies provided a further chance for the visitors to get back into the game but again, nobody was there to meet it at the far post.
Colbeck won a corner on the Town right and after getting the ball back from the flag-kick, the winger sent a driven cross in that Bartless got to ahead of Pearson to claim.
Pearson had to concede a corner soon afterwards to deny midfielder Jamie Chandler a shooting opportunity but Colbeck did well to get the ball clear after a scramble in the penalty area.
A break from Wood saw the right-back run 70 yards after winning the ball on the edge of his own penalty area and beating Glenn Wilson for pace before crossing for Neilson to volley over the bar.
Cook then tried a shot from long range but his drive was caught by Bartlett in the Gateshead goal.
Disley flashed a shot wide from the edge of the box on 65 minutes, before Hannah won a corner on the right two minutes later.
Disley then played a ball through for Hannah but his drilled shot from 20 yards went narrowly wide of the far post.
Nathan Fisher, on for Cummins, had a shot blocked from 20 yards before Town made the points safe once and for all with a fantastic third goal.
Neilson picked the ball up in his own half and showed great pace to take him past a series of would-be challenges before playing it to HANNAH, who blasted it into the net from the edge of the area.
Magnay was booked for a foul on Hannah on the halfway line but Town could not profit from the free kick, as Pearson directed his header off-target when the ball was played into the box.
A Gateshead corner from the right was headed away by Wood but the away side kept possession until Colbeck eventually cleared the danger.
The Mariners then made a double substitution, swapping Hannah and Cook for Elding and Southwell, who formed a new strike pairing for the final 10 minutes of the game.
Substitute Ryan McGorrigan fired over the top for Gateshead as the visitors, who hyad shown little serious threat all evening, looked for a late consolation goal.
Artus replaced Niven in the middle of the Grimsby midfield for the dying minutes of the game.
Four added minutes were played at the end of the game and Town were able to close it out, with a clean sheet providing extra satisfaction for players, management and supporters alike.
And the result meant the Mariners stayed in the play-off positions ahead of Saturday’s visit to league leaders Newport County.