LEWISTON — The breakaway ability of Falmouth High’s top line is no secret.

Thornton Academy worked on containing the Yachtsmen.

“Most of the night we did a good job of shutting that down,” Thornton Coach Jamie Gagnon said.

But Falmouth got the breakaway it needed in the third period, and Henry Norris buried the winning goal for a 3-2 victory in a Class A South semifinal Saturday afternoon at the Androscoggin Bank Colisee.

Robbie Armitage and Reece Armitage also scored for Falmouth. Yachtsmen goalie Spencer Pierce made 21 saves.

Reagan Wintle and Walsh Troiani-Gagner scored for Thornton, and Seth Dube made 26 saves.

Second-seeded Falmouth (16-4) will play in the regional final Tuesday at the Colisee against No. 1 Scarborough (15-2-3).

Falmouth came out with a constant attack. But Thornton Academy’s strength has been its ability to handle such pressure, backstopped by Dube, a freshman goalie who had an impressive rookie year.

“He’s a super-talented kid,” Falmouth Coach Deron Barton said. “He’s small, but he stays square to the puck. For a freshman, outstanding.”

Dube made 13 saves before the Yachtsmen finally broke through. With its second power play, Falmouth created space for its talented forwards. Robbie Armitage skated in from the right circle and beat Dube at 14:17 of the first period. Norris and Chris Camelio had the assists.

“Chris and Henry are such threats, so it opens up a lot,” Robbie Armitage said. “Everyone is feeding off each other. They take away those guys, I’m open.”

Falmouth added to its lead 3:12 into the second period on a wrist shot by Reece Armitage. But back-to-back hooking calls on Falmouth gave Thornton a five-on-three advantage for nearly two minutes.

Falmouth killed off one penalty, but before the fourth skater came into the zone, Thornton scored, with Wintle drilling a shot between Pierce’s pads at 9:47.

A minute later, Chase Wescott went on a rush into the left circle. His shot was blocked, but the puck came out to the slot and Troiani-Gagner one-timed it in tying the game 2-2.

“Penalties kind of took us out (of our game) a little bit,” Barton said.

Falmouth regained control in the third. As Thornton pressured in the Yachtsmen zone, a shot went wide and hard against the glass and bounced out. Reece Armitage passed to his brother, who looked up and saw Norris skating across the red line, with a step on two Thornton defenders.

“Henry read that really well,” said Robbie Armitage, who sent a perfect pass to Norris. Without breaking stride, Norris gathered the puck, skated in and sizzled a shot over Dube’s glove for a 3-2 lead at 2:27 of the third.

“One shot goes wide, we’re pressing, and all of a sudden they’re in a breakaway,” Gagnon said. “They’re dangerous.”

The Trojans had a couple more chances, including two power plays, but Falmouth held on. The Yachtsmen had 29 shots and Thornton took 23, after being dominated in the first period (14-7).

“In the second and third, we played with them,” Gagnon said. “There were times we had scrambles in front of the goal mouth. If we had put those away, it might have been a different game.”

Several of Pierce’s saves came in a crowd as the sophomore stayed composed amid the chaos.