With just about an hour and a half to go before puck drop between Boston and Montreal in the Professional Women’s Hockey League playoff semifinals on Tuesday, the Tsongas Center in Lowell was eerily quiet.

The arena knew the gravity of the moment. With PWHL Boston up two games to none in the best-of-five series, a win would secure them a spot for the green and grey in the first-ever PWHL Finals.

Then a rush of sound broke out from a tunnel leading to the ice, where Boston players were gathered in two circles — one playing keep up with a soccer ball and another having a go at spikeball — as Jack Harlow rapped loudly in the background.

There were smiles all around as players performed the warm-up rituals. Not too loose, not too tight, it was simply business as usual. It seemed like the moment wasn't too big for Boston.

That proved to be true after a 3-2 comeback win in overtime, sending Boston to the inaugural PWHL championship series. In a game as dramatic as Tuesday's, Boston needed to stay every bit as cool as they were pregame to sweat out the historic victory.

Heading into the third, things looked bad for PWHL Boston. Trailing two goals to none, it felt like Montreal would almost certainly pick up its first win of the series. But after the drought of the first and second sets, Boston’s Sophie Shirley found the back of the net just over seven minutes into the third. Amanda Pelkey followed that up with just a few minutes left in the period to tie the game.

That goal ultimately paved the way for overtime, which had become commonplace in the series. The first game went an extra period. Game 2 went a mind-numbing three extra frames. But Game 3 was less of a marathon — just over a minute into overtime, Susanna Tapani hit the game-winning goal to send Tsongas into a frenzy.

It was a slow burn for Boston, for sure. But in the end, the spark found the dynamite.

“I think it took us a little bit to get our legs going. Obviously, didn’t have the start we wanted to,” said head coach Courtney Kessel. “But it’s not how you start, it’s how you finish.”

The win was a sort of reflection of Boston’s season, in which the team won four of its final five contests after a so-so start to the campaign to secure a playoff spot. Pelkey said they’re in a business where they have to find ways to win.

“I think we have the type of players that have played at levels where the pressure is very high and I think that collaboratively, as a group, I didn’t think we were gonna have any issues getting into the playoffs and then being successful being here,” she said.

As Boston goes forward to play against the winner of the Minnesota-Toronto series, the team will need to lean on that experience. And it will need the continued steady presence of goalie Aerin Frankel, who made 32 saves Tuesday night and was serenaded by fans chanting her name following a heroic effort in the previous games in the series.

“She really gave us a chance to win again today,” Kessel said. “Again — I’ve said this before — but that’s why we picked her up in free agency. She’s a tremendous goalie that can make huge saves. And she’s tiny, but man, she plays like a huge goalie. Just can’t get that puck by her.”

Now, as the team prepares to play for the Walter Cup, the chance to bring another banner to Boston is right there for the city's newest squad. And if Tuesday night was any indication, the task isn't too tall for this team.

“I’ve had the privilege of being able to play in Boston before, professionally,” said Pelkey, who used to play for the Boston Pride. “And I think this year, it’s been outstanding. I think you can get a feel of the city. I mean, you have championships all over this city, that’s ingrained here. So hopefully we can add more to it.”