HUNTINGTON — With only 39 seconds remaining in a scoreless first half, Gateway Regional freshman midfielder Ava Auclair gained possession of the ball at the top of the McCann Tech box and lifted a hard shot directly over the goalie into the back of the net to give the Gators a lead heading into halftime.

Auclair’s first goal of the season prompted a huge momentum shift for Gateway, following a first half that featured plenty of ball movement up the field, but an inability to finish around the McCann net.

“It was really exciting,” Auclair said. “After all that hard work from everyone up front, finally getting it was great.”

The Gateway Regional girls soccer team defeated McCann Tech, 4-0, on Booster Field Monday night in a Western Massachusetts Division 4 quarterfinal matchup.

“We were confident that we’d play well,” said Gateway coach Steve Estelle. “I knew they would try a formation to take away some of our offense, but we just kept running our plays and diagonal runs and making our crosses.”

Second-seeded Gateway (13-2-4) will play No. 3 Mount Everett (15-2-2) in the semifinals, at 7 p.m. Wednesday at Holyoke High School.

“We know they’re a good team,” said Estelle. “We won 2-0 in the last game of the season, but we’ll have to prepare for them, go to a neutral site, and play a good game.”

On Monday, the Gators controlled the ball for nearly the entire game, keeping it in Hornet territory consistently enough that Gateway keeper Becca Herman never had to face a shot on goal.

“They played with only one forward and just couldn’t get it past our midfield,” said Estelle. “Our midfielders played well and so did our defense. Gabby Goralczyk, our stopper, played very well. She came up a lot to help start us off.”

Time of possession aside, the game was still tight at halftime.

Auclair added her second goal of the season to put the Gators up 2-0 just nine minutes into the second half. The score wasn’t much different from the one she opened with earlier in the game.

Before a deep launch from the top of the box, Auclair made sure she had space to set up her shot. This time the ball hit the bottom of the cross bar before falling in for the unassisted goal.

“Usually I think too much,” said Auclair. “Coach just told me to kick it and that’s what I did.”

Estelle was pleased with Auclair’s clutch play throughout the night.

“It’s nice that Ava relaxed on those two shots,” said Estelle. “Ava and Rachael (LeBarron) did a great job in the middle.”

Two Gateway players received yellow cards in the game.

Junior forward Jessica Van Heynigen, the Gators’ leading scorer during the regular season, received a card with 13 minutes remaining in the first half on a foul. It was the first foul of the game for either team.

Estelle removed his top scorer in fear of her picking up another card. Van Heynigen’s loss took away a crucial piece of Gateway’s offense.

The referees “put us in a tough spot and I thought the girls responded well,” said Estelle. “We kept playing it to Sam Belardo, she had a strong game.”

Erin Harris and Goralczyk each added unassisted goals as Gateway took a 4-0 lead.