A solitary goal on his full debut from striker Adi Yussuf earned the Mariners a second away win in the space of a week at Hartlepool United.
The Mariners, once again, opted for three at the back – with Shaun Pearson central alongside Andrew Boyce and Danny Collins.
Yussuf, who added the third against Carlisle United on Bank Holiday Monday, was named in the starting XI by manager Marcus Bignot and he repaid that faith with a 35th-minute strike at Victoria Park.
It was a cagey opening from both sides, taking over 20 minutes to spark into life when Dean Henderson raced out quickly to save from former Town favourite Padraig Amond.
The Mariners then enjoyed an excellent spell that saw Omar Bogle and Ben Davies both have efforts saved.
And ten minutes before the break, the men from North East Lincolnshire took the advantage. Brandon Comley picked the ball up in midfield and his pass was left by Bogle for the run of Yussuf, who made no mistake on his left foot from inside the area.
It was almost two just moments later when midfielder Craig Disley rose to meet a Davies corner, only to see his header cleared off the goal-line.
The hosts came out for the second half with renewed vigour but, in truth, they rarely tested Henderson in the visiting goal.
On one occasion the on-loan Manchester United stopper was beaten by a header from Billy Paynter but he has Davies behind him to clear the danger.
United continued to press but the Mariners had their own chance to seal victory with just over five minutes of the game remaining when substitute Dominic Vose flashed a shot just wide from 25 yards.