BOSTON — There have been plenty of best-of-seven series at TD Garden. Sunday morning, it was time for a best-of-three.

For all of the Division 1 marbles – with fans covered in top hats and shamrocks – top-seeded Notre Dame (Hingham) took on No. 2 St. Mary’s in the state championship after a 1-1 split in the regular season.

And in the end, it didn’t take St. Patrick’s Day luck. With a short bench, 9 a.m. start time, three regulation periods, and three overtimes, the Spartans captured the state title in a 5-4 final.

A freshman-to-freshman connection, Alyssa Norden scored the game-winning goal with 2:26 remaining in the third overtime. Bella Freitas made an extra pass to find her teammate along the back post.

“It’s a good feeling,” said Norden, whose goal gave the program its first state title since 2013. “I was just so happy to see our team win at TD Garden.”

But it wasn’t always pretty. St. Mary’s trailed, 3-1, in the second period after a pair of nearly-identical goals from Notre Dame’s Sarah White. 

Good teams don’t pout – they power through. Norden scored on a rebound after a shot from the point by Abby Malcuit to make it 3-2.

Harkening back to last week’s semifinal game against Archbishop Williams, St. Mary’s coach Frank Pagliuca said his team’s motto has been to “keep playing.”

“We were getting outplayed and we just kept playing,” he said. “We kept working, kept grinding.”

Then, the Catholic Central League MVP took things into her own hands – literally and figuratively. Freitas took the puck from the defensive zone, skated past a group of Notre Dame defenders, then potted a breakaway goal to equalize (3-3) with 1:52 remaining in the second period.

“I saw a lot of space when I curled the net and I knew I could maneuver my way through, so that was really good,” Freitas said.

Fast forward to the 7:21 mark of the third, and Freitas made it two. She found a loose puck and lifted it up-and-over Notre Dame goalie Ava Larkin (4-3).

And just when it looked like all hope had been lost on the other side, Notre Dame potted home a rebound (4-4) with seven seconds remaining in regulation – a gut punch past goalie Gianna Tringale.

“Yeah, it’s a little hard… but they put their trust in me, so I’ve got to not dwell on one shot and one goal,” Tringale said. 

Not only did she respond, but Tringale stole the game from Notre Dame, making 14 saves across the three overtime periods.

“I really believe that she won us that game,” Pagliuca said. “She hadn’t started a varsity game until her senior year, so think about how far she’s come.”

Also in the sudden death portions, Freitas drew four penalties, including the one that led to Norden’s finisher. 

“I knew it wouldn’t be easy for me and that they would be all over me,” said Freitas, who finished her debut season with 46 goals. “I just tried fighting off those penalties and getting chances.”

Notre Dame coach John Findley said Freitas is “smart and good with the puck.”

“Yeah, they were penalties,” he said. “They killed us.”

St. Mary’s, which also received a goal from Katy Sarazen, finishes the season with five state tournament wins (Weymouth, Boston Latin, Shrewsbury, Archbishop Williams, Notre Dame), a 23-3-1 record, and, now, a state title to bring back to Lynn.

“I’m so proud of the kids,” Pagliuca said. “It was a total team effort.”