BIDDEFORD — Thornton Academy seniors had gone their entire varsity careers ”“ four years for most of them ”“ without ever having beaten their arch-enemies, Biddeford.

They couldn’t have picked a better time to tie up that loose end.

And they could scarcely have done it with any more drama than they did, Thursday with their 6-4 come from behind taming of the Tigers in a Western Maine Class-A softball playoff quarterfinal at Doran Field.

That’s No. 10 uprooting the No. 2 seed, folks.

Then again, seedings, records, or even dire circumstances mean next to nothing when these schools lock up.

At least they didn’t Thursday, which means that Thornton (10-8) will face No. 3 South Portland (time TBA) in Saturday’s semifinal and not Biddeford (13-4).

“We’ve never beaten them,” said Thornton shortstop Shannon Provost, whose RBI double in the seventh helped fuel a furious four-run rally. “All four years on varsity. So, I’m glad we did. We just found the energy.”

Energy arrived in stages.

Freshman hurler Julia Geaumont stepped into the circle in relief in a tight spot in the bottom of the third, with Biddeford holding a 3-0.

The Tigers were primed to put the game out of reach when they loaded the bases with none away.

However, Geaumont wriggled out of trouble without damage by striking out Sarah Gilblair and Hannah Boucher, then getting Kaleigh Daigneault to fly out.

“Her head’s always in there,” said junior catcher Megan Fifield.

Said Geaumont, “I just knew I had to get the job done without letting anyone score. That’s what I wanted to do.”

The Trojans began to work their way back into contention with a single run in the fifth.

Vanessa McCrum, who delivered the game winning hit in Wednesday’s prelim win at Kennebunk, crushed a lead-off double that grazed the left field fence on its way down.

McCrum was pinch run for by Chrissy Remmes, who later scored on a bunt single by Mary Brown.

Next inning, Hannah Ebling brought in another run with an opposite field double, making it 3-2.

Still, when the Tigers added what appeared to be an insurance run in the bottom of the sixth, Thornton’s comeback hopes appeared to be in serious jeopardy.

Not so, as it turned out.

“When there a 4-2 lead going into the seventh inning,” said Tigers’ coach Leon Paquin, “there are not many times that Biddeford loses. But it’s sports.”

Geaumont got the Trojans going in the seventh, by singling to right.

That was followed by run scoring doubles by Sam Martemucci and Provost.

All of those hitters came through with two strikes against them.

“The adrenaline was just pumping,” said Geaumont. “We came to play and win.”

After Kristin Duross sacrificed Provost to third, Fifield came through with an RBI single to center to make it 5-4. She, too, had fallen into a two-strike hole.

“There are no words for (how excited) we were,” said Fifield.

A bases loaded walk to Brown forced in the final run.

“I think our team likes pressure,” said Provost. “We always come out hitting.”

— Contact Dan Hickling at 282-1535 ext. 318 or dhickling@journaltribune.com.