The Mariners lost out by a single goal as Colchester United came out on top after a tough battle in difficult conditions at Blundell Park.
Heavy rain and high winds provided the backdrop for a keenly-fought lunchtime contest in front of the Sky Sports cameras, with both teams creating good chances in a lively first half.
Clear opportunities proved harder to come by after the break but substitute John-Kymani Gordon struck 12 minutes from time to secure the points for the visitors.
Grimsby came into the game knowing a win would move them to within goal difference of the automatic promotion places in the Sky Bet League Two table, ahead of the division’s other fixtures later in the afternoon.
Three changes were made to the team after last week’s goalless draw at Newport County, with Curtis Thompson making his return to the starting line-up as Callum Ainley and Jayden Luker also came in, with Kieran Green, George McEachran and Jason Svanthorsson missing out.
Jordan Wright began in goal, with Tyrell Warren, Harvey Rodgers, Cameron McJannet and Denver Hume forming an unchanged back four. Ainley, Thompson and Evan Khouri were the midfielders, while Luker and Luca Barrington lined up either side of striker Danny Rose.
Svanthorsson was named on the bench, along with Seb Auton, Lewis Cass, Jordan Davies, Justin Obikwu, Cameron Gardner and Doug Tharme.
Colchester made the journey north looking for a first away win of the season and aiming to move further clear of the relegation zone with three vital points.
Danny Cowley’s team included former Mariners loanee Owura Edwards in midfield, with striker Lyle Taylor aiming to provide the main goal threat.
Edwards was shown the game’s first yellow card within 40 seconds of kick-off for a high challenge on Thompson.
The visitors, playing against the wind, created the first opening through Samson Tovide on the left, although his dangerous-looking cross was turned behind at the far post for a corner.
Wright saw his first action of the afternoon on seven minutes, when a cross from Taylor on the right was met by Harry Anderson. The stopper got down to keep his diving header out, then as the ball bounced around the edge of the six-yard box, Edwards’ shot was blocked.
A strong challenge by Ben Goodliffe on Hume gave Town a free kick just inside the Colchester half on 12 minutes, although Rodgers could not generate enough power on his header from it to trouble goalkeeper Matt Macey.
Goodliffe then had to react quickly to deny Rose as the hosts looked to capitalise on a mistake in defence, then Hume set off on a run down the left before finding Rose inside the penalty area but Macey got down to make a good save from his low strike.
A Barrington cross proved just too high for Rose to connect with a header as Town went forward again, then Anderson was caught offside at the other end at thhe end of a move down the Colchester left.
Mandela Egbo saw the yellow card for a foul in midfield after the referee had allowed an advantage and Town worked the ball forward for Barrington, whose shot was blocked for a corner.
Goodliffe got to a Luker cross first soon afterwards, then Wright was called into action again just after the half-hour as he dived to stop a low shot from Tovide.
Rodgers beat Taylor to a cross from the away left moments later, then a ball into the box from Warren led to a Town corner at the other end but Macey did well to claim Hume’s far-post delivery.
Barrington was just wide with a low shot from 25 yards, before the hosts were given another opportunity to create danger when Ainley was pulled back just inside the Colchester half. Hume’s free kick was cleared and although Town retained possession, they were unable to test Macey.
Three added minutes were played at the end of a fiercely-contested first half, with strong challenges continuing to come in from both sides.
But with no further chances created at either end, the game remained goalless at the interval.
SECOND HALF
No changes were made before the restart and Luker linked up with Warren to win the first corner of the second half four minutes in. Hume’s delivery broke for Thompson on the edge of the box but his attempt was blocked.
Defender Aaron Donnelly needed treatment after being caught by Rose in a challenge in the air, while Hume was also treated for a cut on his arm.
A deflected strike by Taylor looped up and over the bar for a Colchester corner but with the striker off the pitch after receiving treatment, the ball from the flag went out at the far post for a goal kick.
Neither goalkeeper had been tested in the opening 15 minutes of the half and a Hume free kick from the right was comfortably dealt with by the away defence.
Thompson draged Tovide down to concede a free kick inside the Grimsby half and it turned into a corner when Arthur Read’s delivery was headed behind by Rodgers. From the flag, the visitors had the ball in the net when Anderson turned it home from close range but the offside flag had already gone up against the winger.
The disallowed goal seemed to galvanise Towwn and they pushed forward afterwards, creating a number of openings but lacking a final ball to unlock the Colchester defence.
Luker fired wide from the edge of the box, before Wright got down to tip a shot from Tovide around his near post for a corner at the other end.
Edwards met a Taylor cross at the far post but volleyed wide, then a low ball across the box from Khouri was cut out for a corner after a flowing move on the home left. Town retained possession from the flag-kick until Ainley lifted an attempt over the bar from 20 yards.
Jack Payne and Gordon replaced Taylor and Edwards as Colchester made the first substitutions on 75 minutes. Town responded by sending Obikwu and Davies on, with Rose and Thompson making way.
A Goodliffe cross was cleared for a ccorner by Rodgers and Goodliffe was first to the ball from the flag but his header was blocked and cleared.
Soon afterwards though, the deadlock was broken and the visitors took the lead. A loose ball was won on the Colchester right and they worked it back across the box, with the substitutes combining as Payne found GORDON to side-foot past Wright.
Svanthorsson replaced Barrington on 81 minutes as Town looked to get themelves level.
Obikwu won a corner two minutes later as he ran onto a ball over the top from Davies, although the ball from the flag was eventually dealt with by the away defence.
A minimum of seven added minutes gave Town further opportunity to secure a positive result, with Colchester boss Cowley sending Alex Woodyard on for Read in their latest change.
Obikwu ran onto a ball into the box but Macey was equal to his low strike to turn it behind for a corner, although the Mariners were unable to profit from the flag-kick.
And the visitors closed out the remainder of the contest to secure their first victory on the road of the campaign.
Town now have a break from action before returning to Blundell Park to face Accrington Stanley on Tuesday, December 3.
Town: Wright, Warren, Rodgers, McJannet, Hume, Ainley, Thompson (Davies, 76), Khouri, Luker, Rose (Obikwu, 79), Barrington (Svanthorsson, 81)
Subs not used: Auton, Cass, Gardner, Tharme
Attendance, brought to you by Elegant Beds: 4,952