GRIMSBY Town’s 12-game unbeaten run came to an end as Cheltenham Town won at Blundell Park to move back to the top of the National League.
Centre-back Aaron Downes scored the only goal of the game midway through the second half to ensure all three points went back to Gloucestershire.
In a game between two well-matched teams in front of a 5,218 crowd, the Mariners had the better of things in the first half, creating the majority of the attacking opportunities but failing to test visiting keeper Dillon Phillips on enough occasions.
After the interval, Cheltenham were the better side and after a spell of pressure from the visitors, Downes struck.
Town set out to try and haul themselves level but they were not able to find a goal and instead, were left to reflect on what was just their third defeat of the season.
The Mariners were unchanged from the side that beat Harrogate in the FA Cup last week, with James McKeown in goal behind a defence of Richard Tait, Toto Nsiala, Shaun Pearson and Connor Townsend.
Danny East started on the right of midfield, with Craig Disley and Craig Clay in the middle and Nathan Arnold operating on the left.
Omar Bogle and Padraig Amond were the strikers, with Scott Brown, Josh Gowling, Jack Mackreth, Marcus Marshall and Jon-Paul Pittman all named as substitutes.
Cheltenham came into the match sitting in second place in the table and knew they would go top with a win.
Their side included former Town loanees Daniel Parslow and Harry Pell, while they would be looking to strikers Billy Waters and Danny Wright to make the difference in front of goal.
A low cross from Bogle was cut out for the game’s first corner on five minutes but Grimsby were unable to make the opportunity from the flag count, as Townsend’s low ball came back for him to put another cross in that curled out at the far post.
Arnold did well to win a corner after intercepting the ball in midfield and running it forward. This time, East’s low ball was played back to him but Amond could only prod wide at the far post from his follow-up cross.
At the other end, a Rob Dickie free kick was cleared by Disley, before Waters won a corner on the left, which led to no problems for the Town defence.
The first real chance of the game came on 16 minutes, when good work by Bogle sent East through the middle and but after getting into the penalty area, his shot was well blocked by visiting keeper Dillon Phillips. Town kept possession and a cross came in from the right but Amond could only head it wide.
A free kick came for the Mariners on 21 minutes on the right touchline and East’s ball was headed on by Pearson but nobody could get to it and it bounced wide.
Arnold missed the target with a shot from 30 yards as Town continued to create the better attacking opportunities, finding their feet after Cheltenham had made the more composed start to the game.
Another Amond header dropped wide of the far post on 25 minutes, before Townsend won a corner on the left a minute later, which was punched clear by Phillips.
A Town penalty appeal came on 27 minutes for a handball and although the referee agreed the offence had taken place, he adjudged it to have been just outside the box. Bogle stepped up to take the free kick but his shot hit the Cheltenham wall.
The visitors were yet to cause any real problems for McKeown in the Grimsby goal and that continued on 35 minutes, when Wright blasted a 20-yard shot over the bar.
Good defending by Townsend saw him deal with a dangerous-looking cross by heading it out for a throw-in, then McKeown got down to stop a shot from midfielder Kyle Storer.
At the other end, Bogle managed to shield the ball out of play for a Town corner on the right with 39 minutes on the clock but Townsend’s delivery was hammered clear by Pell.
A foul on Pell three minutes before the break gave the away side a free kick in a central position, 25 yards from goal. Midfielder Kyle Storer’s shot was caught by McKeown.
Waters also had a shooting chance for Cheltenham soon afterwards but his attempt was weak and went wide.
An opportunity for the Mariners came in the last minute of the half, as Bogle got on the end of a through-ball and squared it for strike-partner Amond but the Irishman’s shot was blocked by Phillips.
One additional minute was played at the end of the half and with no further chances created by either side, the game remained goalless at the interval.
Town started the second half on the attack and they won an early corner on the left, which was headed up in the air by Pell and then caught by Phillips.
Storer tried his luck with a long-range shot for Cheltenham on 50 minutes but McKeown was able to watch it fly over his bar.
Waters was then presented with a shooting chance after Wright beat Nsiala to a ball in the air but his first-time effort on the turn lacked direction and went wide at the near post.
Disley was shown the first yellow card of the game after he brought Pell down inside the Cheltenham half.
The visitors then created their best chance so far, attacking down the left and moving the ball across the penalty area to Jack Partham, whose shot was blocked by McKeown.
Cheltenham were having a good spell and they attacked again soon afterwards, although the move ended with Pell slicing a shot high and wide from 20 yards.
At the other end, a free kick was swung in by Townsend and pushed out for a corner by Phillips. The ball from the flag was cleared by Storer.
Nsiala gave away a free kick for obstruction after initially doing well to stop a Cheltenham attack. Midfielder Jack Munns took it but his shot from 20 yards was pushed away from danger by McKeown.
The pressure from the visitors was building and more danger came when Wright linked up with Waters before seeing a shot blocked. Munns then looked to profit from the rebound but the ball was put out for a corner.
The away team did not have to wait long until they finally broke the deadlock though, as the low ball into the box from the flag was helped on to unmarked centre-back DOWNES, who had the time and space to guide it past McKeown and into the net.
Town boss Paul Hurst’s response was to send Marshall on in place of Tait, with East moving to right-back as Marshall lined up on the wing.
Soon afterwards, a second Grimsby substitution saw Pittman replace Bogle, as Hurst looked for something different in attack to change the course of the game.
A diagonal ball into the box from East was headed forward by Arnold on 77 minutes but the ball was cleared from danger.
Townsend put a cross in from the left a minute later and it was met by Marshall but he could not direct his glancing header towards goal.
The third and final home substitution saw Brown come on in place of Clay in the centre of midfield with a little over 10 minutes left to play.
A cross from East was put out for a corner, which quickly turned into another one, but the Mariners could not create a goalscoring opportunity from the flag.
Disley missed the target with a half-volley from 25 yards that went over the bar and into the Pontoon Stand as Town kept pressing in an attempt to get an equaliser.
Brown had to concede a corner to stop Wright from shooting on 86 minutes and before the kick was taken, Lee Vaughan was sent on in place of Partham.
Three added minutes were played at the end of the game but Town were unable to find a way past Phillips and the visitors were left to celebrate their win.
The Mariners are next in action on Saturday, when St Albans City are the visitors to Blundell Park in the first round of the FA Cup.