Souhegan's Libby Kennedy drives against Pinkerton's Eliana Henry during Sunday's Division I semifinal at Bill Ball Stadium in Exeter. Kennedy scored the game-winning goal for the Sabers with 18 seconds left in overtime. (Photo by Joe Marchilena/NH-HighSchoolSports.com

EXETER – A year ago, they took a big step by reaching the Division I girls lacrosse semifinals.

Now the Sabers of Souhegan High School are taking center stage. Libby Kennedy’s goal with 18 second left in sudden death overtime gave the No. 3 Sabers a 9-8 win over No. 2 Pinkerton in the Divison I semis at Bill Ball Stadium on Sunday. Now Souhegan will take on No. 1, unbeaten Portsmouth (19-0) for the title on Tuesday here at 5 p.m.

Portsmouth edged Souhegan in last year’s semis, and destroyed No. 4 Exeter 19-3 in the other semifinal last night.

The Sabers (14-3) on Sunday were trailing 6-5 going into the final period, and the Astros got the lead to 8-5 and still led 8-6 with just over three minutes left. But the Sabers’ Isabelle Stevenson decided enough was enough and she scored three straight in the final 3:38 to send the game to overtime.

“I am incredibly, incredibly proud,” Souhegan coach McKinley Curro-Sbordone said. “We have a relatively young team, so to be able to claw back and fight, it was great.

“Izzy Stevenson wanted that so bad. She took our team on our back, everyone was behind her. We talked right before we went into overtime, and I had no doubt that we would be able to get the last one (goal).”

The game was not unlike the 9-8 win the Astros had over the Sabers during the regular season.

“Both sides fought hard, and it obviously took extra time to decide this one,” said Pinkerton coach Katie Bourque. “Lacrosse is a game of runs, they had their runs, and we had our runs. Unfortunately, they had theirs at the end.”

For the Sabers, Stevenson had three goals, Lanai Hickman and Kennedy a pair, and Emersynn and Averie Curran one each. Delaney Summes had three and Hannah Lisauskas two to lead the Astros.

(Evan Applebaum of the Lawrence Eagle Tribune contributed to this report.)