SACO — With the ball at her talented feet and the game tied in overtime, Cheverus forward Annie Vigue said she tried to just stay calm as she collected a long free kick from sophomore back Rachel LaSalle, beat her defender and stared down Thornton goalie Ava Lomax.

“I’m making sure I stay composed, picking a corner, making sure I don’t over hit it over the net,” Vigue said.

Vigue stayed calm and drilled the game-winner into the top right quadrant with 9:04 left in the 15-minute golden-goal overtime period giving No. 5 Cheverus (11-3-2) a 3-2 win at No. 4 Thornton in Tuesday’s entertaining Class A South quarterfinal.

Thornton (10-4-1) had sent the game to overtime when Quincy Thibault scored with just 67 seconds left in regulation. Thibault raced to a loose ball in the box after Cheverus goalie Evelyn Rush stopped one of Charlotte Belanger’s hard shots from distance, but didn’t control the rebound.

Cheverus advances to Friday’s regional semifinal at No. 1 Scarborough (14-1), which won its quarterfinal 5-0 over No. 8 South Portland. A year ago, Scarborough eliminated Cheverus on its way to the Class A title.

Stags Coach Craig Roberts said his team learned to play loose and bounce back from adversity, as it did both after the tying goal and when Belanger scored directly off her own corner kick just 5:16 into the game for a 1-0 Thornton lead.

“Tonight I thought we played our best soccer of the year,” Roberts said. “We showed some resilience. If you drop all the self doubt, drop all the fear and just play free, play without fear then you’re not going to have any regrets. So that’s kind of been our mantra: No fear, no regrets.”

Cheverus tied the game on a goal from Finley Brown, who got loose on a breakaway and was able to get her shot away and past a charging Lomax at 15:09 of the first half. Cheverus continued to pressure with Vigue making dangerous moves along one wing and Sophia Monfa using her speed and crosses from the other side of the field to get create chances for Brown, Sofia Prothier and first-sub Alaina Holmes.

The Stags went ahead on a set play when LaSalle, a sophomore defender, took a free kick from just a bit outside the box that freshman defender Olivia Vigue headed home 5:34 before the half.

In the second half, Thornton tilted the field in its favor, with Belanger taking strikes from distance, Thibault working the ball deep and Hadley Stoddard making several nice runs. Stoddard had two good chances to tie the game early in the second half, but her header off a corner kick was caught by Rush and a close-range shot was blocked by Cheverus midfielder Jillian Foley.

“Super proud of our girls for fighting until the very end and getting that tying goal to send it to overtime,” said Thornton Coach Natalie Sharland. “It comes down to capitalizing on your opportunities. We had our moments. We just didn’t put the ball back in the net.”