With three of the league's top four teams losing on Friday and Saturday, a win for the Mariners on Sunday at Polytec Stadium would have propelled them to first place.
But a first-half volley from the Glory's Susan Phonsongkham would ultimately deny Central Coast the three points.
They at least earned a draw, however, after Trimis's 'Olimpico' equaliser, when she curled a stunning ball from a corner into the net in the 61st minute.
The result puts the Mariners just one point behind leaders Melbourne City (19), equal on points with Canberra United but third on goal difference.
Central Coast could have added more to their tally, though, as they missed prized opportunities throughout the match, posting nine shots on target compared to their opponents' four.
"I just got told to put the ball on top of the keeper, and somehow it went in. I'm really happy with the goal," Trimis told Paramount+.
"This is my first time taking corners in my career.
"We created a lot of chances, which is a good sign."
A win for Perth could have helped them into third position, but a draw means they only rise to sixth.
They will also have to wait until February for the opportunity to win on the road, having not secured a victory away since October 31.
"It's one of our better performances considering the scoreline," Phonsongkham said. "But, I don't think we played as well as we do at home.
"We had plenty of opportunities. It's just unfortunate that we weren't clinical in the box."
The Mariners dominated territory from the outset as golden boot contender Annalise Rasmussen missed two clear opportunities to open the scoring.
In the 34th minute, Perth's Isobel Dalton took advantage of some lazy defence, lofting the ball into the box and finding Phonsongkham on the volley.
After Perth's goal, Central Coast had a flurry of chances, and in the 61st minute, they finally broke through when Trimis scored with her 'Olimpico'.
Both teams went end to end after the stunning goal, and the Mariners thought they had taken the lead when Trimis centred the ball to Rasmussen, who planted it past Teresa Morrissey. But that effort was called offside.
Each side tried desperately for a winner in the last 10 minutes but couldn't find one.
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