Port Vale's midweek win against Blackpool saw them leapfrog six places to regain a play-off spot, but they would need to make it two in two against Grimsby if they were to maintain their position.
The Mariners' early hard work was shattered in the 18th minute when Austrian international Andreas Lipa capitalised on a headed clearance with a low volley from the edge of the box which zipped past visiting keeper Aidan Davison.
Vale found a second two minutes later with a copycat goal when Sam Collins popped up at the same range and drove a thunderous strike into the bottom corner.
The scoring didn't stop there with the Valiants turning on the style for their third.
Steve McPhee advanced on the Grimsby box with a darting run and unselfishly spread the ball to the arriving Mark Bridge-Wilkinson who steadied himself 25 yards from goal and delicately chipped Davison to score.
The away side grabbed one back seconds later again in a spectacular manner, with Jason Crowe chipping the ball up for Phil Jevons to coolly finish into the top left corner of Jon Brain's goal.
In an amazing half, Brian Horton's side added a fourth on the stroke of half time with Billy Paynter tapping in Collins' rebounded free-kick from barely two yards out.
Vale finished off the rout on 74 minutes with Bridge-Wilkinson firing home an unstoppable shot from 25 yards for his second of the game.
A delighted Horton said: "At the moment we're looking like a decent side collectively, and, with no disrespect to the 18-year-old lads, we've had a full strength bench today.
"The squad is littered with players from big clubs and no league experience but they do ever so well."