Jaze Kabia's late header snatched a narrow victory as Grimsby became the first team to defeat Fleetwood at Highbury Stadium since August.
After ending their nine-game winless league run by beating Shrewsbury three days ago, the Mariners made it back-to-back victories to leapfrog above Fleetwood in to 12th place in League Two.
Grimsby's Jude Soonsup-Bell had the game's first big opportunity after 16 minutes when Kieran Green's pass put him in behind, but he dragged his shot wide.
It took Fleetwood 56 minutes to have a shot of any description when Mark Helm's attempt was comfortably held by Grimsby goalkeeper Jackson Smith.
But the hosts were inches away from taking the lead when Ched Evans struck the outside of a post after sliding in to meet Ethan Ennis' corner round the back.
Just when it looked like the game was flickering out, the Mariners stole the win in the 89th minute when Darragh Burns' cross picked out fellow substitute Kabia, who headed into the top corner.
Report supplied by PA Media.
Wild: 'A rubbish game of football'
Artell: 'A terrific performance'
