GRIMSBY substitute Danny North made an instant impact at Field Mill with a late winner within three minutes of joining the action.
North raced almost half the length of the pitch to seal Grimsby's third successive win.
Stags had gone ahead through Michael Boulding on 31 minutes and, had Barry Conlon's headed finish five minutes later not been ruled out for offside, things may have been very different.
But, roared on by over 1,300 away fans who had their transport to Field Mill paid for by chairman John Fenty, the visitors levelled three minutes from the break through Paul Bolland.
Stags did have their chances after the break and Matt Hamshaw was only just wide while keeper Phil Barnes saved smartly at his near post from Stephen Dawson, both within 13 minutes of the restart.
But after those it was all Grimsby and they came close several times before North bagged their deserved winner with just seven minutes to go.
Disappointed Mansfield manager Billy Dearden said: "I though the result was fair enough. We were poor today - the worst we have played at home since I came here.
"We set off sloppy for the first 20 minutes but then we got among it and scored a good goal.
"Scoring just before half time gave Grimsby a real lift.
"I was disappointed we let them get the cross in from the left and then it was one of my ex-players that was left all alone unmarked to volley in at the far post which was also disappointing.
"I thought Grimsby knocked it around quite well today, though we didn't play half as well as we can. But that's taking nothing away from Grimsby.
"I thought we looked a bit jaded in the second half and there were one or two heavy legs out there.
"There are a few heads down in the dressing room right now. But I have a lot of young kids here and so I have to be careful about laying into them.
"We have had a good discussion and we are fortunate to have another game on Tuesday to try to put things right."
Grimsby had recently lost seven games on the trot, scoring only once in that time. But they had then hit back with a bang with two wins and 10 goals in those two games ahead of today's clash.
The Stags welcomed back Conlon after his three match ban.
He replaced Brown who had been struggling all week with a groin strain and made up the numbers on the bench.
White had to gather a low Newey cross at his near post in the fourth minute as the game made a slow start.
Hamshaw over-hit Stags' first corner, then Conlon sent a lobbed attempt straight into the arms of keeper Barnes.
Hunt had a shot blocked and then Bolland got in a low shot straight at White as the visitors went looking for an opener.
Grimsby carved out the best chance so far on 18 minutes as sloppy defending gave the visitors a corner which saw Boshell pick out Fenton who headed powerfully over from five yards.
Within a minute Conlon powered a dipping shot over at the other end.
Fenton was booked on 22 minutes for upending Hamshaw in full flight and Whittle followed a minute later for his challenge on Dawson.
Conlon was again too high from 25 yards on 25 minutes.
But Stags were ahead on 31 minutes as Boulding struck against his old club.
White's long kick reached Conlon who turned and crossed towards Boulding whose first time attempt struck a defender but rebounded kindly to him and he made no mistake at the second time of asking from five yards.
Fenton almost levelled three minutes later as Jelleyman headed across his own box and the Mariners' man met it on the full with a rasping volley just wide.
Conlon found the Grimsby net with a powerful stooping header from Dawson's cross on 36 minutes but an offside flag cut short the celebrations.
Hamshaw got away down the right and got in a cross which Barnes spilled and was relieved to see the ball fall the wrong side of the lurking Conlon.
But it was the visitors who squared things up on 42 minutes.
Newey's cross from the left found Bolland ghosting into the far side of the box unmarked. He got his shot on target and White's fingertips could only touch it onto the post and watch it bounce into the net.
Bolland had the first attempt of the second half when he was just wide after having a go from 25 yards.
Mansfield weathered some good Grimsby pressure before forcing two successive corners.
Passes from D'Laryea and Conlon moved the ball from right to left where Hamshaw cut in to rifle a low shot narrowly wide of the far post.
A Stags break saw Hamshaw set up Dawson with a pass pulled back into his path and Barnes had to turn Dawson's low shot round his near post.
Toner was wide from 18 yards as Stags tried to clear a 62nd minute corner.
Play continued to swing from end to end and Boulding won a free kick 20 yards from goal which Conlon sent low straight at Barnes.
Boshell's name was added to the book for his foul on Dawson and Buxton joined him for bringing down Patterson.
Stags cleared the free kick as far as Boshell which, from 30 yards, he blasted narrowly wide.
Bolland was afforded too much space and get in a low shot that White was behind.
Brown replaced goalscorer Boulding for the last 20 minutes.
On 72 minutes Newey curled a shot just wide of the near post.
Stags replied with a corner which Hamshaw put over and Conlon met with a glancing back header that sailed just over.
Gritton was replaced by Reet on 75 minutes.
The Mariners sent on North for Patterson on 80 minutes and within three minutes he broke away from just inside the Mansfield half onto a through ball and showed great pace and coolness to pick his spot and beat White all ends up.
Grimsby manager Alan Buckley said: "That is three wins on the trot and that was the best we have played in those three games.
"We dominated from the kick off and had a great start, but then to be fair Mansfield got back into it and scored.
"But we equalised at a great time and I thought it was important to be on level terms at half time.
"Then in the second half we played so well we totally dominated, created chances and went so close to scoring a second goal before Danny's (North) late winner.
"I was tempted to change the formation in the second half from 4-5-1 to 4-4-2 but the midfield three all did well and none of them deserved to be taken off.
"Then I replaced Martin (Patterson) because he had run his socks off and Danny got us a superb winner.
"The fans were fantastic, even at a goal down they were behind us. There were so many of them for an away game, it was great."
North raced almost half the length of the pitch to seal Grimsby's third successive win.
Stags had gone ahead through Michael Boulding on 31 minutes and, had Barry Conlon's headed finish five minutes later not been ruled out for offside, things may have been very different.
But, roared on by over 1,300 away fans who had their transport to Field Mill paid for by chairman John Fenty, the visitors levelled three minutes from the break through Paul Bolland.
Stags did have their chances after the break and Matt Hamshaw was only just wide while keeper Phil Barnes saved smartly at his near post from Stephen Dawson, both within 13 minutes of the restart.
But after those it was all Grimsby and they came close several times before North bagged their deserved winner with just seven minutes to go.
Disappointed Mansfield manager Billy Dearden said: "I though the result was fair enough. We were poor today - the worst we have played at home since I came here.
"We set off sloppy for the first 20 minutes but then we got among it and scored a good goal.
"Scoring just before half time gave Grimsby a real lift.
"I was disappointed we let them get the cross in from the left and then it was one of my ex-players that was left all alone unmarked to volley in at the far post which was also disappointing.
"I thought Grimsby knocked it around quite well today, though we didn't play half as well as we can. But that's taking nothing away from Grimsby.
"I thought we looked a bit jaded in the second half and there were one or two heavy legs out there.
"There are a few heads down in the dressing room right now. But I have a lot of young kids here and so I have to be careful about laying into them.
"We have had a good discussion and we are fortunate to have another game on Tuesday to try to put things right."
Grimsby had recently lost seven games on the trot, scoring only once in that time. But they had then hit back with a bang with two wins and 10 goals in those two games ahead of today's clash.
The Stags welcomed back Conlon after his three match ban.
He replaced Brown who had been struggling all week with a groin strain and made up the numbers on the bench.
White had to gather a low Newey cross at his near post in the fourth minute as the game made a slow start.
Hamshaw over-hit Stags' first corner, then Conlon sent a lobbed attempt straight into the arms of keeper Barnes.
Hunt had a shot blocked and then Bolland got in a low shot straight at White as the visitors went looking for an opener.
Grimsby carved out the best chance so far on 18 minutes as sloppy defending gave the visitors a corner which saw Boshell pick out Fenton who headed powerfully over from five yards.
Within a minute Conlon powered a dipping shot over at the other end.
Fenton was booked on 22 minutes for upending Hamshaw in full flight and Whittle followed a minute later for his challenge on Dawson.
Conlon was again too high from 25 yards on 25 minutes.
But Stags were ahead on 31 minutes as Boulding struck against his old club.
White's long kick reached Conlon who turned and crossed towards Boulding whose first time attempt struck a defender but rebounded kindly to him and he made no mistake at the second time of asking from five yards.
Fenton almost levelled three minutes later as Jelleyman headed across his own box and the Mariners' man met it on the full with a rasping volley just wide.
Conlon found the Grimsby net with a powerful stooping header from Dawson's cross on 36 minutes but an offside flag cut short the celebrations.
Hamshaw got away down the right and got in a cross which Barnes spilled and was relieved to see the ball fall the wrong side of the lurking Conlon.
But it was the visitors who squared things up on 42 minutes.
Newey's cross from the left found Bolland ghosting into the far side of the box unmarked. He got his shot on target and White's fingertips could only touch it onto the post and watch it bounce into the net.
Bolland had the first attempt of the second half when he was just wide after having a go from 25 yards.
Mansfield weathered some good Grimsby pressure before forcing two successive corners.
Passes from D'Laryea and Conlon moved the ball from right to left where Hamshaw cut in to rifle a low shot narrowly wide of the far post.
A Stags break saw Hamshaw set up Dawson with a pass pulled back into his path and Barnes had to turn Dawson's low shot round his near post.
Toner was wide from 18 yards as Stags tried to clear a 62nd minute corner.
Play continued to swing from end to end and Boulding won a free kick 20 yards from goal which Conlon sent low straight at Barnes.
Boshell's name was added to the book for his foul on Dawson and Buxton joined him for bringing down Patterson.
Stags cleared the free kick as far as Boshell which, from 30 yards, he blasted narrowly wide.
Bolland was afforded too much space and get in a low shot that White was behind.
Brown replaced goalscorer Boulding for the last 20 minutes.
On 72 minutes Newey curled a shot just wide of the near post.
Stags replied with a corner which Hamshaw put over and Conlon met with a glancing back header that sailed just over.
Gritton was replaced by Reet on 75 minutes.
The Mariners sent on North for Patterson on 80 minutes and within three minutes he broke away from just inside the Mansfield half onto a through ball and showed great pace and coolness to pick his spot and beat White all ends up.
Grimsby manager Alan Buckley said: "That is three wins on the trot and that was the best we have played in those three games.
"We dominated from the kick off and had a great start, but then to be fair Mansfield got back into it and scored.
"But we equalised at a great time and I thought it was important to be on level terms at half time.
"Then in the second half we played so well we totally dominated, created chances and went so close to scoring a second goal before Danny's (North) late winner.
"I was tempted to change the formation in the second half from 4-5-1 to 4-4-2 but the midfield three all did well and none of them deserved to be taken off.
"Then I replaced Martin (Patterson) because he had run his socks off and Danny got us a superb winner.
"The fans were fantastic, even at a goal down they were behind us. There were so many of them for an away game, it was great."
