SOUTH BERWICK — When it’s close and low-scoring, every goal is magnified, each defensive stop special.

Second-seeded Marshwood High put one big check in each category – goal and save – in a 1:25 span late in Saturday’s Western Class A semifinal girls’ lacrosse game to secure its 4-2 win against No. 3 Thornton Academy.

Leading 3-2, Marshwood sophomore Hannah Costin set up senior tri-captain Korinne Bohunsky for the final goal with 4:25 to play. Costin had dropped and recovered the ball four times in the possession, but kept her cool and her eyes open, hitting Bohunsky as she cut behind the Thornton defense that had to extend its pressure.

“We connected eyes and really felt it on that play,” Bohunsky said. “We have a saying on this team to just feel it, and Hannah and I really work well together.”

With three minutes remaining Marshwood goalie Emily Kahler, another senior tri-captain along with midfielder Lindsey Poirier (1 goal), stared down fast-breaking Faith Sinclair and flashed her stick across her body to make a top-corner save.

“Every save is important so there is a lot of pressure on you, both goalies, both sides,” said Kahler, who finished with 10 saves. “Any goalie always gets nervous in a one-on-one like that, but I just look at the ball and track the ball and hopefully hope for the best.”

Marshwood (11-3) will host No. 4 Scarborough in Wednesday’s regional final.

Marshwood’s only other appearance in a regional final was a 2012 loss to Scarborough, when Coach Bernie Marvin’s seniors were freshmen.

Thornton had one final scoring bid that ended with Sinclair missing the net on a free-position shot. Thornton was 1 of 10 on free-position shots – the situation when an offensive player is given an open channel toward goal after a defensive infraction, with defenders lined up along the arc.

“We always practice putting our sticks in the middle and they stop the ball with their sticks,” Kahler said. “They had at least four that way. … Even if the (shots) did get through, it took away a little speed and that helps me out.”

Marshwood scored twice on free-position goals in the defense-dominated first half: Poirier at 9:36 and Bohunsky at 14:39, both beating Thornton keeper Allie Spinney (5 saves) with shots to the top of the net delivered from a high stick position.

Katie McCrum and Amanda Cyr scored for the Trojans (10-4). Costin scored Marshwood’s third goal.

“It was a classic playoff game,” Thornton Coach Craig Agreste said. “The bottom line is they capitalized on the free positions in the first half and we had opportunities.”