Perth coach Tony Popovic hopes Socceroos forward Chris Ikonomidis won't be out for long with a dislocated shoulder, after Glory tightened their grip on the A-League Premiers Plate with a 3-0 away win over Central Coast.
Perth, who are unbeaten away, with eight wins and four draws, pulled six points clear of second-placed Sydney on Sunday, with three rounds remaining.
Joel Chianese and Dino Djulbic scored in the first half hour then Neil Kilkenny added a penalty just before the hour mark.
They notched a club record 10th clean sheet in a season, while the Mariners made some unwanted club history by losing a fifth straight home game.
Popovic described it as an excellent performance by Perth and was upbeat about Ikonomidis, who came off the ground just before halftime.
"He seems in in very good spirits I think he's had it previously a few years back," Popovic said.
"His movement is very good. We don't feel that it's serious but we won't know the extent of the injury till he gets an MRI in the next day or so and we're hopeful that he's not out for too long."
Perth's fluency and ball movement was good and they bounced back well from last week's home loss to Melbourne Victory.
"The conditions were very humid. It was a heavy pitch, but I thought the players played with real confidence and belief and obviously last week's result didn't affect them," Popovic said.
The Mariners' caretaker coach Alen Stajcic was proud his side fought to the end.
"We actually had plenty of moments within the match, we probably just lacked quality in the front third," he said.
"They scored from two set pieces, a corner and a pen, and the first goal we had six on three and it goes through a couple of players legs."
Perth hit the lead in the 12th minute when a series of quick-fire passes culminated in Chianese cutting inside and firing a fine shot across Ben Kennedy into the far corner.
Glory doubled their advantage in the 29th when Djublic rose above a pack of players to direct a Kilkenny header home for his first goal in four years.
Kilkenny sealed the points when he fired home a spot-kick after Jacob Melling cut down Castro.
Jordan Murray fired wide from close range in the first half for the Mariners, but the hosts struggled to create clear-cut chances against a defensive well marshalled by the returning Matthew Spiranovic.
Only fans 3,744 attended, just 14 more than the Mariners' smallest ever A-League home crowd.