Pools surged up the table courtesy of the comprehensive victory with Paul Robinson's hat-trick the highlight at Victoria Park.
The hosts took the lead on 19 minutes when Mariners player/manager Paul Groves turned a free-kick into his own net.
Within 60 seconds, Pools had doubled their advantage when Robinson slotted home a penalty after Marco Gabbiadini was fouled by Simon Ford.
Gavin Strachan curled home a free-kick on 28 minutes after another foul on Gabbiadini while Ritchie Humphreys made it four just past the half-hour mark.
Grimsby earned themselves a brief respite three minutes after the interval when Jonathan Rowan scored but Robinson helped himself to his second on 56 minutes.
Gabbiadini deservedly put his name on the scoresheet on the hour before Eifion Williams sent the home fans into seventh heaven midway through the second period.
The Mariners were unable to stem the tide and Robinson completed his hat-trick with ten minutes remaining to secure Pools' biggest win in many a year.
