GRIMSBY Town put themselves firmly in the race for automatic promotion as they earned a priceless away victory against Dover Athletic.
Lenell John-Lewis marked his return to the starting line-up by scoring what turned out to be the only goal of the game with just six minutes on the clock.
Town were comfortable at the break but they were anything but for the majority of the second half as the hosts attacked in search of a leveller.
But the Mariners held firm to secure all three points and move to within three points of league leaders Barnet.
John-Lewis replaced Jon-Paul Pittman in the only change to the Town XI from the home win over Eastleigh on Saturday.
James McKeown started in goal, with Carl Magnay, Toto Nsiala, Shaun Pearson and Gregor Robertson in defence.
Nathan Arnold, Craig Disley, Craig Clay and Christian Jolley were the midfielders, with Ollie Palmer starting alongside John-Lewis in attack.
The Grimsby substitutes were Pittman, Ross Hannah, Scott Brown, Paul Bignot and Daniel Parslow.
After a quiet opening to the game, the Mariners took the lead on six minutes, after Palmer’s pass found Arnold. He in turn gave it to JOHN-LEWIS and after the striker’s initial shot was blocked by home keeper Mitch Walker, he followed it up to crash the ball into the net from close range.
Dover responded by winning a corner but they were unable to turn it into a chance in front of goal.
McKeown had to come off his line to meet a back-pass from Jolley, before a shot from Nicky Deverdics had to be blocked for a corner by Pearson. The ball from the flag was headed away by Nsiala.
A foul by Jolley gave the home side a free kick near the Town corner flag on 20 minutes but it was headed clear by Robertson at the near post.
Stefan Payne won a corner off Clay as the home side continued to look for an equaliser but again, it was dealt with by Robertson before a return ball into the box was headed away by Disley.
Another free kick came Dover’s way soon afterwards but Payne’s near-post flick caused no problems for the Town defence.
At the other end, Jolley missed the target with a shot on 25 minutes, before a foul on Pearson gave the Mariners a free kick near the halfway line that went off Magnay for a throw-in after McKeown had sent it towards the danger zone.
Palmer was presented with an opportunity when defender Richard Orlu blasted the ball against him but the Mansfield loanee could not take advantage as he hit keeper Walker with his shot.
Sean Raggett was shown the first yellow card of the night for a foul on Jolley just after the half-hour but the resulting free kick was dealt with by the Dover defence.
A run from John-Lewis at the end of a sharp passing move led to a defender having to step in and ensure the only damage was a throw-in.
Another Town free kick came after defender Connor Essam was booked for a foul on Jolley but as before, the Mariners were unable to profit from the free kick.
Robertson was the first Town player to go into the referee’s notebook when he was yellow-carded for a foul eight minutes before the break.
A decision then went against Clay two minutes later but Deverdics’ powerful drive from the free kick was straight at McKeown.
A Grimsby corner on 41 minutes almost led to a second goal when Arnold’s ball was met by Nsiala but Walker got down to stop the centre-back’s header.
Dover were looking to play high balls into the Town box but were having little success as McKeown had enjoyed a relatively comfortable half in the away goal.
Two added minutes were played at the end of the opening period and a Dover attack ended when Deverdics floated a cross wide for a goal kick.
No further chances were created by either side before the half-time whistle sounded, ensuring Town went into the dressing rooms with their lead intact.
Neither side made any substitutions before the restart and Town won an early throw in a dangerous position but it led to an offside decision against Jolley.
At the other end, Magnay had to concede a corner after a break by Ricky Modeste. It almost led to a goalscoring opportunity as the low ball from the flag was lost by McKeown but Disley was there to clear.
Another corner to the hosts came on 52 minutes but they were unable to make it count as the ball was eventually put behind by Deverdics.
Striker Tom Murphy was the third Dover player to be booked after he fouled Robertson, before Palmer looked to create a chance for John-Lewis but his cross was cleared at the near post.
Murphy made way for Dan Holman on 58 minutes as Dover made the first change of the evening.
A free kick was lifted into the Town box by Deverdics after Disley was penalised for a foul and Pearson had to put it out for a corner, which was dealt with comfortably by the Mariners defence.
The home side were having a promising spell, aided by a string of set-piece opportunities, although there had still been little to worry McKeown.
Jolley was replaced by Pittman on 64 minutes, with Dover still on top in terms of possession and territory.
Payne had a shot for the hosts four minutes later but it went past the post for a goal kick and Town’s lead remained in place.
Another effort, this time from midfielder Chris Kinnear, also failed to trouble the Grimsby keeper as the home side continued to attack in search of an equaliser.
Town had shown little attacking threat since half-time but they won a corner on 75 minutes, although Arnold’s ball was headed wide by Nsiala.
John-Lewis volleyed an effort over the bar, before Brown replaced Palmer as Town boss Paul Hurst shuffled his pack.
A foul by Robertson with 11 minutes to go gave Deverdics another chance to curl a free kick into the Grimsby box. Disley got to the ball first to head it clear.
A challenge from Sean Francis stopped John-Lewis as he looked to launch a quick break for the Mariners, before James Poole replaced Payne and Barry Cogan came on for Kinnear for the hosts.
Cogan had a chance on 86 minutes after the ball was flicked past Nsiala but with McKeown advancing, the substitute could not turn it on target.
Town looked like they were about to have an opportunity when Pittman raced clear but Orlu got back to stop him.
Arnold then had a run through the middle, although his shot was saved by Walker.
Dover then had three chances to get something from the game, with the first coming after Brown gave the ball away in midfield but the home attackers could not punish him.
Then, McKeown had to be at his best to tip a Deverdics header away for a corner as the hosts looked to force a leveller.
Dover were to come even closer from the flag-kick, when the ball appeared to have been forced over the line by Raggett, only for McKeown to grasp it as the home supporters were starting to celebrate.
Four added minutes were signalled and after Bignot replaced Clay, another corner came when McKeown had to tip a shot from Poole over his bar in the last of those minutes. It was headed away for another corner, which was only half-cleared before a shot went just past the post.
Town had escaped on several occasions and they were ultimately to hang on for all three points to move within striking distance of the top of the table.
The Mariners are on the road again when they travel to Welling United on Saturday.