The Nix stretched their unbeaten run at Westpac Stadium to 21 matches with a 2-0 A-League victory over Central Coast on Sunday.
A classy goal to Leo Bertos in the 10th minute and a powerful Paul Ifill strike in the 61st were enough for the Phoenix to lodge a first win of the season, having endured a bye and a 3-3 home draw with Gold Coast last weekend to start their campaign.
It was also the seventh successive time that the Phoenix have kept a clean sheet against the Mariners.
Aside from the goals, chances were at a premium in a scrappy affair which featured some loose passing and a relatively conservative approach from both teams despite the fine conditions.
Ifill said it was pleasing to lodge three points despite a display lacking fluency.
"The lads dug in and we need to do that more often, get a couple of goals up and kill the game off," he said. "It's something we did a lot better today than we did last week.
"It was one of those games when I just couldn't get going and the goal's covered up an average performance really.
"I've said it all preseason, I think games here (Wellington) will take care of themselves, we'll be very hard to beat," he said.
"But we've got to be harder to beat on the road."