Jon Shaw's second-half strike helped Gateshead to a third straight win in the Blue Square Bet Premier against struggling Grimsby.
Yemi Odubade slotted a pass through the Mariners' defence for Shaw, who drilled a right-foot shot past James McKeown into the Grimsby net.
Frankie Artus went closest for Grimsby, blasting an 18-yard shot over the bar.
But the Mariners failed to create any further chances to leave them with just one win from six games.
Gateshead: Farman, Odhiambo, Curtis, Clark, Rents, Gate, Turnbull, Cummins (Nix 72), Odubade (Mulligan 89), Shaw, Moore (Fisher 72). Subs Not Used: Deasy, Baxter.
Goals: Shaw 58.
Grimsby: McKeown, I'Anson, Kempson, Pearson, Wood, Coulson (Makofo 60), Church (Elding 75), Disley, Artus, Hearn, Duffy (Spencer 60). Subs Not Used: Thompson, Freeman.
Booked: Church, Disley, Wood.
Ref: Ross Joyce (Cleveland).