AUGUSTA — Third-seeded Monmouth found itself in a battle for its tournament life Monday morning against No. 6 Waynflete, a team it didn’t face in the regular season.

The Mustangs didn’t gain any breathing room until the final 30 seconds when three players converted single free throws to seal a 45-40 victory.

Monmouth (17-3) advanced to play No. 2 Boothbay in a Class C South semifinal Thursday at the Augusta Civic Center. Waynflete finishes at 11-9.

There were five ties and six lead changes in the quarterfinal Thursday. Junior Abbey Allen led the Mustangs with 16 points and eight rebounds while teammates Tia Day added 10 points. Flyers senior Annika Brooks led all scorers with 25 points and nine rebounds.

“They play a lot of B schools and they beat Falmouth this year, which is a tournament team in A,” Monmouth coach Scott Wing said of the Flyers. “They’re a good, solid team and they’re the type of team that gives us a hard time, two big girls and a point guard we couldn’t get to turn the ball over.”

Monmouth took the lead for good early in the second half when Day made two free throws and Hannah Anderson and Emily Grandahl converted layups to make it 36-31. There wasn’t much scoring after that as both teams missed shots or took their time to run some clock. After shooting 10 for 27 in the first half, Monmouth went 4 of 16 from the floor in the second.

“We were trying to be more patient with the ball because they weren’t allowing us to shoot outside much,” Wing said. “We were trying to get the ball inside, which takes more time. And we were horrendous (15 of 28) from the free throw line.”

The Mustangs took away Lydia Giguere, Waynflete’s leading scorer, holding her to four points, while the Flyers held Day in check and allowed her just a couple of three-point attempts, which she missed.

“I know for me they were trying to take away the three-point line,” Day said. “When we saw that ,we just tried to take it to the hoop and draw some more fouls on them.”

Day opened the fourth quarter with a driving layup in traffic to make it 42-35, but Brooks answered by sandwiching a bank shot and a hook in the lane around a free throw to make it 42-40. Neither team scored a basket after that. Allen, Anderson and Day hit single free throws in the final 27 seconds to put the game away. Giguere was ruled to have fouled Allen intentionally, which gave the Mustangs two shots and the ball.

“I think she was running after her and the girl stopped and she kind of pitched into her,” Waynflete coach Mike Jeffords said. “The way I saw it she pitched forward. We certainly coach them to go after the ball.”

Seven different players scored for Monmouth in the first half, led by Allen with 12 points. The junior forward moved into the starting lineup early in the season and has performed well since.

“I’ve just stepped it up when I need to,” Allen said. “If other players aren’t making the play, I need to make them.”