Victory moved to second spot on the standings and seven points behindSydney FC with a game in hand after a dominant second-half performance against Paul Okon's Mariners.
Kevin Muscat's side took a 1-0 lead into half-time then pressed home their advantage with goals from James Donachie and Marco Rojas, who netted twice in two minutes.
Substitute Trent Buhagiar scored a consolation goal for the Mariners in the final minutes.
Sydney FC remained unbeaten after 12 games with a 4-0 hammering of defending champions Adelaide United.
Goals from Slovak Filip Holosko, a brace from Alex Brosque and another from Rhyan Grant sealed Sydney's win and left Adelaide at the bottom of the standings with a lone win.
Brisbane Roar are third after extending their unbeaten run to 10 games following a 1-1 home draw with Western Sydney.
Second-half goals from Corey Brown and Wanderers Spanish skipper Dimas Delgado cancelled each other out.
Melbourne City lie fourth after a thrilling 3-3 draw with Perth Glory.
City's Uruguayan skipper Bruno Fornaroli missed a stoppage-time penalty after red cards to Glory's Dino Djulbic and City's Argentine attacker Fernando Brandan.
City were awarded three penalties in the at-times spiteful encounter, with Fornaroli scoring one and having the other two saved by Liam Reddy.
Fornaroli finished with two goals with Glory's Spanish maestro Diego Castro also netting a brace.
Newcastle moved into fifth spot after holding Wellington Phoenix to a 2-2 draw.
The Jets twice had to come from behind at home with goals from Andrew Hoole and Andrew Nabbout cancelling out strikes from former MelbourneVictory duo Kosta Barbarouses and Brazilian Gui Finkler.
