Stonington — The Waterford High School girls' lacrosse team huddled in a circle in front of its bench, arms linked, rocking back and forth in unison moments before taking the field for the Eastern Connecticut Conference tournament semifinals Wednesday night.

Fifty minutes later, the Waterford bench flooded onto the field and flocked toward the net, mobbing senior goalkeeper Ivanna Hugo in a pile of bodies and screams.

"We all worked hard to stay tight throughout the whole game," Hugo said, "and I feel like that paid off."

In its biggest game of the season, the second-seeded Lancers (14-3) defeated defending Class S state champion Stonington 10-7. Waterford plays rival East Lyme in the finals beginning at 5 p.m. Friday at Waterford.

It was a familiar opponent for the Lancers, who split their first two meetings with Stonington this season and shared the ECC Small Division title. Waterford tipped the balance its way with a strong offensive attack, stellar performance from its defense and communication worthy of its goalkeeper's praise.

"We knew that we weren't gonna have an easy game," Waterford coach Audrey Montanaro said. "I think we were prepared to play 150 percent for 50 minutes, and we did."

Despite slipping into an early 1-0 hole, Waterford spent much of the rest of the first half dominating possession, with the defense spoiling Stonington opportunities as well.

Junior Leah Petrini finished the game with four goals, three of which came in the game's first 17 minutes. She gave the Lancers a lead they never relinquished. Senior Riley Dimmock also scored three goals.

"Oh my gosh," Petrini said with a broad smile. "It's crazy, I'm just so excited."

Even after Petrini took a pass to the face that popped off her goggles (she left the game to get observed on the sideline at the 3:59 mark), third-seeded Stonington couldn't muster a run and Waterford ended the half leading 5-3.

An onslaught of three goals in just over 10 minutes to start the second half pushed the Lancer lead to 8-3, while tight defense prevented Stonington from running out in transition. The Bears' stagnant offense prompted bemoaned murmurs of frustration from their home crowd.

Stonington junior Hannah Johnson rocketed a free position shot into the back of the net at the 13:10 mark to trim the lead to 8-4, but Hugo caught two consecutive free position shots by Johnson at 12:34 and 11:15 in her stick that could have cut the lead to two.

"She's really grown into herself this season ... she found this groove and she's been unstoppable," Montanaro said. "She's found ways to stop the ball that we never thought would work."

Dimmock and Petrini scored the next two Waterford goals and a spirited Stonington comeback of three goals in under 30 seconds to cut the lead to 10-7 proved too late.

Waterford milked the final three-and-a-half minutes off the clock before turning it over to Stonington, which was able to muster up one last shot as the buzzer sounded.

Hugo blocked it, and the celebration began.

As Waterford waited to board the bus and depart, the team gathered in groups across the sidewalk, snapping pictures and laughing, savoring the moment.

"It's amazing, it's such a great feeling and we worked really hard this season," Hugo said. "Our hard work paid off."

• In Wednesday's other semifinal, Vanessa Vurno contributed four goals and four assists to power top-seeded East Lyme past No. 4 Ledyard 17-7. Gabby Fiengo scored four goals while Kendall Roberts and Steph deLaforcade each had three goals for the Vikings (13-4), who led 10-3 at halftime. Goalie Alex Rose had 15 saves. Liz Austin and Brooke Scahill had three goals apiece for Ledyard (9-7-1).