BOSTON — The Boston Bruins’ 4-2 come-from-behind win against the St. Louis Blues in Game 1 of the Stanley Cup Final resulted from a game plan that would have worked as well in the 1950s as it did Monday night.

The Bruins didn’t panic when they fell behind 2-0. They were relentless. Defenseman Torey Krug even lost his helmet and delivered an old-school, Original Six-style hit on Robert Thomas with the game on the line in the third period.

“He just got a haircut a couple of days ago, so he was looking pretty good,” Bruins teammate David Pastrnak said of the moment.

Both teams were playing so well coming into the Stanley Cup Final that it was impossible to say which team had more momentum.

But the Bruins are clearly that team now heading into Wednesday’s Game 2. The Bruins have won eight consecutive postseason games and have outscored the opposition 32-11 in that span.

“I think we can be even better and we are going to have to be,” said Blues winger David Perron.

The Bruins showed some rust after not playing a game for 10 days between the Eastern Conference final and the Stanley Cup Final. The Blues claimed a 2-0 lead on goals by top-line players Brayden Schenn and Vladimir Tarasenko.

However, the Bruins rediscovered their game in the second period when they out-shot St. Louis 18-3.

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“We weren’t perfect, but I don’t think we’re ever expected to be perfect,” said defenseman Connor Clifton, who scored Boston’s first goal. “We pushed back.”

Brad Marchand did contribute an empty-netter, but the Bruins won this game on the strength of two goals by defensemen (Clifton and Charlie McAvoy) and a game-winner by fourth-line center Sean Kuraly.

Their balanced scoring has been crucial to their success since the first round.

“If you get contributions from your back end, if you get contributions from your bottom-six forwards, you’re going to win a lot of hockey games,” Krug said.

Both teams have depth, but Boston’s showed more in Game 1. Boston coach Bruce Cassidy used his No. 1 line (Marchand, Patrice Bergeron and Pastrnak) against the Blues’ No. 1 line (Jaden Schwartz, Schenn and Tarasenko). But then Cassidy assigned the Kuraly line to check the Schenn line and the team had more success. 

“They use everybody,” St. Louis coach Craig Berube said. “They use all six D. They are a good team, but we are a good team, too.”

Krug’s helmet-less hit also seemed to give the Bruins a lift.

“It’s part of a game – momentum swings,” Krug said. “It gives your team a boost of energy. I don’t know what they were feeling on their bench, but if it pushes them back and catches them off-guard, it’s great for our team. I think it gave our team energy.”

Krug said he didn’t know if it was smart to charge down the ice to make the hit without a helmet, but he did it nonetheless.  

“You don’t want to mess with that guy,” Clifton said. “Don’t make that guy mad.”