Lois Maynard scored the only goal of the game as Halifax maintained their play-off push with a win over promotion rivals Grimsby.
Maynard opened the scoring with a stunning strike from 25 yards.
Ryan Crowther came close to making it 2-0 in the closing stages but his effort was blocked before Paul Marshall fired over the rebound.
The result sees Halifax leapfrog Grimsby into third spot after a seventh consecutive clean sheet.
Grimsby Town manager Paul Hurst told BBC Radio Humberside:
"I don't like losing. We lost to the in-form team in the league, so we've had that two weeks running with Woking and then Halifax. I didn't think there was anything in the game in all honesty, we've lost to an excellent strike.
"I think all night it was a frantic night to be honest. I think when they go 1-0 up they're just happy to clear the ball and sort of not too interested where it goes.
"We had the best chance in the game there's no getting away from that."
- 5PearsonBooked at 18mins
- 3ThomasBooked at 33mins
- 7ColbeckSubstituted forMcLaughlinat 69'minutes
- 4KerrBooked at 44minsSubstituted forThanojat 82'minutes
- 28TounkaraSubstituted forHannahat 69'minutes
- 20MaynardBooked at 37mins
- 15RobertsBooked at 73mins
- 23SmithBooked at 13mins
- 29BoltonBooked at 90mins
- 40SpencerSubstituted forCrowtherat 74'minutes
- Wayne Barratt
- Shots on Target