Mike Giordano walked into the Scarborough High girls’ locker room at halftime of their Class AA South semifinal Wednesday night against Thornton Academy and knew he was going to have to instill some confidence, and faith, in his players.

While the Red Storm led by seven, starting freshman point guard Emerson Flaker had suffered an injury to her right leg in the final seconds of the second quarter. Giordano stayed with Flaker on the court for long minutes while she was treated.

“I told the kids, you can allow that to define why we don’t win,” said Giordano. “Or you can use it to inspire you to win. There’s no question they chose the latter.”

Second-seeded Scarborough never faltered in the second half, using a tenacious 2-3 zone to confound Thornton Academy’s shooters and defeat the third-seeded Trojans, 40-31, at Cross Insurance Arena. Lindsay Fiorillo and Caroline Hartley combined for six foul shots in the final 85 seconds to secure the win.

“They showed a lot of character,” said Giordano.

The Red Storm (16-4) will play No. 1 seed Gorham at 7 p.m. Saturday at Cross Insurance Arena. The Rams beat Massabesic, 51-43.

Thornton finished 14-6, with two losses to Scarborough.

Flaker never returned in the second half and Giordano didn’t know the extent of her injury. “All I know is she’s smiling, like the rest of them,” he said.

Una Djuranovic, who scored 10 points, said the injury certainly inspired the Red Storm. “I think that really pushed us more than really we thought we were capable of,” she said.

Scarborough started slowly, trailing 8-4 after one quarter, but found its stride in the second with a 10-0 run. Flaker tied it at eight with her only basket of the game, then Elisabeth LeFebvre gave Scarborough the lead for good with an offensive rebound. Hartley and Fiorillo each hit two foul shots, and suddenly it was 14-8.

The Trojans got within 14-12 on a 3-pointer by Addisen Sulikowski, but Fiorillo (15 points) countered with a 3 and Djurnovic scored on a drive to make it 19-12.

Thornton had trouble getting into an offensive flow after Scarborough switched to its zone. The Trojans were forced to shoot 3-pointers, and they struggled there in the cavernous building, hitting just 1 of 13 in the first half and 3 of 25 overall.

And after Scarborough got rolling, the Trojans struggled to keep up.

“Our mistakes kept compounding and they took advantage of them,” said Thornton Coach Eric Marston. “We obviously didn’t make the right adjustments. I expected us to make shots. We’ve got some of the best shooters in the league and we just missed.”

Thornton found a rhythm in the fourth and got within 34-29 on a 3-pointer by Hannah Cook with 1:47 remaining. But the Trojans had to foul to get the ball back, and the Red Storm hit their free throws. For the game, Scarborough was 14 for 18 at the line.

“That’s what wins you big games,” said Giordano.