HINGHAM – The first day of the Hingham Showcase was as tightly matched as expected Tuesday night at Pilgrim Arena, but the best finish was saved for last.

By scoring the game-winning goal from the point with 3:39 left in overtime, eighth-grade defenseman Emma Burke delivered the knockout punch as the Notre Dame Academy of Hingham girls hockey team beat St. Mary’s of Lynn, 2-1, in a battle between the MIAA Div. 1 power rankings’ top two teams.

Both played premier defense much of the way, combining to allow just 32 shots on goal. Each of the Cougars’ (12-4-2) goals came from defensemen, too, rallying from a first-period deficit to avenge an earlier loss to the Spartans (18-2-1).

“The girls all played a part,” said NDA head coach John Findley. “It’s what the (state) tournament’s all going to all be about. You’ve got to work hard and it’s going to take every little effort from every girl.’”

Playing their first game without one of their top defenders, the Spartans slowly adjusted to their new defensive look in the first period. But as Megan Donato (18 saves) picked up nine saves in a shutout opening frame, freshman Bella Freitas put St. Mary’s on the board with a highlight-reel goal on its only shot.

While Ava Larkin (11 saves) produced six saves in the second, senior defender Lucy DelGallo snuck the game-tying score through a tight window with about six minutes left in the frame.

Neither team could produce many dangerous looks on the attack in the third period, with St. Mary’s only getting four shots on goal and NDA producing three. Freitas used her speed to challenge Larkin a couple more times the rest of the way, but the senior goalie didn’t waver

Overtime saw NDA mostly carry play despite another Spartans’ shot, and Jocelyn Gray found Burke for a heavy shot though traffic and over Donato for the win.

“That play that Jocelyn Gray made, the pass back to Emma Burke (was great), and Emma just fired it,” Findley said. “What a great goal. The girl had no chance, that was like one of those things. Chase (Harmon) was standing in front of the net, what a shot. … I was happy for her.”

Hingham (15-5-1) didn’t need the same theatrics as NDA to come away on top in the game prior, instead using two goals from its second line to power a 2-1 win over Andover (7-8-3).

The Harborwomen controlled the puck much of the way in a 31-9 shot advantage, but needed sophomore Alexa Harris (goal, assist) and freshman Callie Crean to step up for goals against a standout performance from Golden Warriors senior Anna Marble (29 saves).

“That was a fast, physical team … as the game went on we kind of picked it up,” said Hingham head coach Courtney Turner. “Throughout the season we’ve faced some adversity. We’ve had games where we get 40 shots and we lose 1-0. We’ve had those tough games and … we’ve learned how to put it away. It might not be the exact game we want, but we come out with the W.”

Freshman Shea Richardson and sophomore CC Flynn led the Harborwomen defense in disrupting Andover breakouts and zone entries.

Twice Marble was the top player in the Golden Warriors’ penalty kill, picking up four saves in each. Hingham continued to bang on the door, though, and got on the board with 6:05 left in the second period on a 2-on-1. Harris carried the puck along the left wall before crossing it to Crean, who banked it off the far post for the 1-0 lead.

Marble stood on her head for the first 10 minutes of a 12-save third period. Harris then potted her own with 4:22 left in the third off a Hannah Lasch assist, proving to be a much-needed insurance goal.

“I think (our) first two lines are pretty interchangeable,” Turner said. “They just work their butt off and it shows on the scoreboard. They’re putting pucks in in front of the net and that’s what we need. That’s what you need from your first, second line. Third line goes out there, works hard, gets it deep.”

Andover got a goal back with 1:48 left on a score from Abby Walles, but Hingham’s defense held.

Hingham’s Callie Crean, right, and Andover’s Rose Memmolo collide during a Hingham Showcase girls hockey clash Tuesday. (Staff Photo/Stuart Cahill/Boston Herald)