Central Coast's A-League Premiers' Plate defence remains alive, but only with the dullest of heartbeats after Sunday's heated 1-0 win over Brisbane in Gosford.
Bernie Ibini struck the winner in the 34th minute, guaranteeing the Mariners a home semi-final and a week off in the first week of the playoffs.
The hosts showed glimpses of their best despite only arriving back in Australia on Friday after a mid-week Asian Champions League loss in Japan, and were particularly threatening during a 20-minute patch in the opening half.
But there were few other reasons to celebrate for the home crowd of 7225 at Bluetongue Stadium.
Mariners coach Graham Arnold certainly wasn't pleased - but for other reasons.
Arnold was given an official warning in the first half for expressing his disappointment to referee Alan Milliner, after Roar counterpart Mike Mulvey had walked down to his technical area.
Arnold was again incredulous in the dying stages, when the referee failed to end the match after four minutes of injury time.
Table-topping Western Sydney have all but sealed top spot. With two rounds to play, they lead the Mariners by five points and need only one draw, or better, from their remaining clashes with Sydney FC and Newcastle.
A slip-up from the Wanderers, who have won 10 on the trot, seems highly unlikely.
More pertinently, on current form, the Mariners are anything but certainties when they visit Adelaide United next Sunday.
The Roar, desperate for the three points that would boost them into the top six, had the better of a second stanza that featured plenty of end-to-end football.
Mariners goalkeeper Mat Ryan did well to keep out Stefan Nijland, who had only the 'keeper to beat, while Nijland also hit the woodwork with a free-kick.
It was on-song Roar goalkeeper Michael Theo who kept the visitors in the game during a one-sided first half, with the Mariners taking charge from the 24th minute when Michael McGlinchey unleashed a stinging strike.
Theo did well to tip McGlinchey's effort over the bar, then came up with an even more impressive double save from the resultant corner.
Ibini somehow managed to blaze over the top of the goal after Theo's double parry, but made amends for his error with his seventh goal of the season.
Ibini tiptoed around would-be tacklers Shane Stefanutto and Luke Brattan before slamming the ball inside Theo's near post.
The Mariners had a handful of other chances before halftime, with Daniel McGreen's header hitting the woodwork, but couldn't come up with the goods and were made to sweat in the second half.