Liam Hearn hit his second hat-trick in three games as Grimsby thumped Barrow.
Hearn notched his first from Lee Ridley's long pass before Paul Smith levelled from a free-kick.
The Mariners regained the lead when Hearn tapped in Craig Disley's pass only for Jack Mackreth to equalise for the visitors from Richie Baker's ball.
Hearn wrapped up his treble with a header before substitute Anthony Elding put some gloss on the result with two fine finishes.
VIEWS FROM THE DRESSING ROOM
Grimsby Town joint manager Paul Hurst told BBC Radio Humberside:
"Defensively, we were poor. We were delighted to win and we wanted a result rather than a performance but we can't hide behind the fact that we were at sixes and sevens defensively.
"We've not got it 100 per cent right. We're okay going forward. The goals we were confident we would score are starting to come . But, at the other end, there's a hell of a lot of work to do.
"We'll be having a word with Liam Hearn. He's come from a level below and he's got a lot to learn still but we've seen that he's a real talent and he can go far."