TOPSHAM — The Portland girls’ lacrosse team isn’t trying to test the limits of what a group of athletes can endure. It just seems that way.

Friday’s Eastern Class A semifinal was the latest example of the “slingshot” metaphor the Bulldogs have been embracing.

“They came up with that at a team dinner, I think,” Portland Coach Cameron McManus said. “The girls say ‘slingshot.’ You get pulled back but it just shoots you forward.”

No Bulldog moves forward more rapidly than Isabel Stehli, and it was her three-goal burst that allowed Portland to overcome a four-goal deficit and ultimately derail second-seeded Mt. Ararat 10-9 in double overtime at Ryan Field.

That followed a four-overtime victory over Cheverus just 48 hours earlier and put the Bulldogs into Wednesday’s regional final against top seed Messalonskee. It’s heady stuff for a program that had never advanced past the first round before.

“That’s so important in team sports is that, yeah, things may not be going your way, but you still have all this time left to play the game, especially in lacrosse where you can score so quickly and so easily,” McManus said. “If you get in your head and get down about it, that’s what can really put you out of a game.”

Portland (9-5) is never out of a game these days, thanks to eight dedicated seniors who have lifted the program out of the doldrums, and an ever-changing rotation of heroes like Stehli, Ella Coose and Merritt Ryan.

Mt. Ararat (12-2) broke free with four goals in a three-minute span of the second half to take an 8-4 lead. The last two were by Erin Tome, who finished with four goals and was a persistent thorn in Portland’s side with her speed.

Stehli, who had been contained until that point, then notched her natural hat trick over the next six minutes to bring the Bulldogs within 8-7 and get the Portland bench pulsating with energy again.

“We really just remembered why we were here and how far we’ve come,” Stehli said. “We knew if they were going to get up by that many, we could get it right back in the same amount of time if we just put in the effort and worked together.

“It was just a shift in our momentum. We were seeing each other better. Something clicked and we just went with it.”

Alison Nolan’s third goal of the game put the Eagles ahead 9-7.

Ellis Linsmith cut that lead to 9-8 with 5:22 left and then it was Ryan’s turn to provide the dramatics.

The junior midfielder, who is also a basketball standout, was surprised to turn her shoulder and find an opening near the crease and took advantage to net the tying goal with 21.3 seconds left. It was the 100th goal of her career and the most important, but only for the time being.

In the first overtime, Ryan raced in for a free-position score to give her team a 10-9 lead with 5:13 left to play. It was her fifth goal of the game, and Portland’s defense, led by goalkeeper Elizabeth Victor, made it stand up.

The Bulldogs ran out the clock in an intermittent rain, then rushed the field to celebrate another improbable victory for a program that is making a habit of them.

“We knew they couldn’t get another goal because we didn’t want to have four more overtimes,” Ryan said of her team’s late-game defense. “Our adrenaline took over. We just played really high pressure, high intensity.

“It’s a good step for our team. It’s really awesome.”