For the second successive week, it was striker Gary Jones who won all three points for the Mariners. Last week at Brentford, it was a neat shot early in the second half that decided matters and this time it was a superb diving header that was the difference between the two sides.
Nick Hegarty got away down the left and his fine cross was despatched like a bullet past goalkeeper Carl Muggleton after 62 minutes.
It was the sort of match where one goal was always going to be enough to decide it and it was Grimsby who always looked the likeliest to get on the scoresheet.
For Mansfield, the salient fact was that they rarely looked like scoring and on the evidence of this display, their placing at the foot of the table is not going to be temporary.
It could have been a different story had not Grimsby wasted a great chance early on. Experienced midfielder Paul Bolland was gifted the ball and could have run several yards further, but took his shot too early and blazed his shot well wide.
After a great start Grimsby lost momentum as Mansfield enjoyed their best spell, without ever seriously testing Grimsby keeper Phil Barnes.
In the second half, as the temperature fell, the surface became tricky and good football was at a premium.
This was only Grimsby's second home win of the season in the league and their second-successive 1-0 win, which for a side which could not keep a clean sheet until recently was quite a feat.
For Mansfield, their off-field problems, regarding the ownership of the club, are clearly having an effect on the playing side and they face a real fight to retain their Football League status.