A first-half brace from Perth striker Daniel McBreen has seen the Glory cast Central Coast out of the Hyundai A-League finals for the first time through a solid 3-1 victory at ME Bank Stadium on Sunday afternoon.
Although an injury-hit Glory looked slightly vulnerable heading into the encounter, McBreen helped ease some of the worries within the first minute as he fired home past Danny Vukovic.
McBreen doubled the tally in the 11th minute and despite Central Coast gaining control of possession, Andrija Jukic flicked in the third just before the break.
Adam Kwasnik pulled one back within four minutes of the re-start but Central Coast struggled to hit the target from there on as the Mariners lost just their second game to the Glory since the new competition began.
"The first half was outstanding and in the second half we tried to contain them a little bit, but they scored and got a bit of wind in their sails," Glory coach Dave Mitchell said.
"We had to make a couple of changes to adjust to that and we went to three at the back with Jamie Coyne in midfield, and he did an outstanding job covering in front of the back three there."
"There's a few boys who were out injured as well, so it's good to see the boys came in and performed well."
Perth's third win in a row sees Lawrie McKinna's men lose any mathematical chance of making the finals this season with two games remaining.
But Brisbane's surprise win over Sydney on Saturday night means the fourth-placed Glory are not assured of making the play-offs just yet.
Perth may be six points clear of the Roar with a substantially better goal difference, but the Brisbane side can't quite be counted out as it plays Perth in the final round.
Despite coming into the game under an injury cloud, McBreen shrugged off any concerns within 48 seconds of kick-off as the former Fury man scored the Glory's fastest Hyundai A-League goal.
A hopeful long-punt forward from Chris Coyne was fumbled by Mariners' defender Chris Doig, allowing McBreen the chance to take possession and slot it home.
It only got worse for the Mariners ten minutes later as McBreen doubled the advantage.
Mariner Andrew Clark appeared to have a long ball from Adriano Pellegrino covered but the midfielder didn't count on a determined effort from Perth's Scott Neville, who pressured Clark into going to ground in a tangle of legs close to the goal-line.
First to his feet, Neville crossed into the box for another McBreen finish, his fourth goal in four matches since heading west from North Queensland.
"You wouldn't expect those mistakes in an under-10 team you know," said disappointed Mariners' boss Lawrie McKinna.
"We've gone from having the best defensive record in the league to hopping goals that are just not good enough."
Central Coast had the chance to pull one back in the 25th minute when Glory stopper Aleks Vrteski, deputising for the injured Tando Velaphi, fumbled a header from Alex Wilkinson, but Pellegrino was on the goal-line to hook it away.
Despite being two down the Mariners were enjoying a good spell of possession and Pedj Bojic came within inches of the upright from a free kick.
But the Glory added another in the shadows of half-time from a corner as Andy Todd sent a bouncing ball forward, allowing Jukic flick