Jeremy Swayman flashed a Star-Spangled smile.
As Todd Angilly belted out a stirring rendition of the national anthem Saturday night at TD Garden, the Bruins goalie’s grin was ear-to-ear.
When the last note was hit, Swayman dropped his mask and shined brightest, stoning the Maple Leafs to lead the Bruins to a 5-1 win in Game 1 of their first-round Stanley Cup series.
Swayman, given the nod in the Boston net after a week of super secrecy, boarded it up nicely, making 35 saves — several super — to earn his first playoff win since 2022.
“Dream come true,” said Swayman. “It’s such a privilege to play in this league and for this city. And taking that first lap and hearing the fans, seeing the towels is a pretty emotional feeling.
“And we just understand how hard it is to get here and what a great opportunity it was, so I couldn’t wipe that smile off my face the whole night. Pretty spectacular.”
Jim Montgomery wouldn’t completely commit to breaking his season-long goalie rotation, but did acknowledge, “it’s going to be hard to go away from Sway … He played a terrific game.”
He wasn’t alone.
Jake DeBrusk scored a pair of power-play goals, and Pat Maroon provided skill, savvy, and strength up front.
The nastiness started even before the rubber hit the ice, as Brad Marchand and Max Domi traded shoulder shoves until they were told to knock it off.
Calle Jarnkrok, who was subbing in for ailing Leafs star William Nylander — “It’s tough to start a playoff without him,” said Toronto boss Sheldon Keefe — had the visitors’ best opportunity to strike first, but Swayman robbed him with a right pad flash.
The Bruins got on the board first at 2:26, when Johnny Beecher, playing in his first career playoff game, cashed in on a 2-on-1.
Maroon dug a puck out of the corner and hit speedy Jesper Boqvist on a breakout with Beecher. With only Timothy Liljegren between them and Ilya Samsonov. Boqvist waited for Liljegren to commit, and when the Toronto defender hit the deck, Boqvist hit Beecher with a soft saucer pass and the rookie snapped it under Samsonov’s glove.
“I blacked out a little bit,” Beecher said of his celly. “I was just kind of in the corner, hit the glass, and I was just kind of screaming and the boys were all jumping on me, so it’s one I’ll never forget.”
The secondary assist was Maroon’s first point in Black-and-Gold duds.
It was sweet redemption for Beecher, who was banished to Providence after a rough outing in Washington last week.
“I thought Beecher was really good. I think that’s the best game he’s ever played as a Bruin,” said Montgomery.
The Bruins nearly increased the lead on the power play (Simon Benoit high stick on Charlie Coyle), but Coyle’s one-timer from the slot just missed.
Maroon gave his new devotees something more to cheer about moments later when he dumped Liljegren into the Bruins bench with a big thump.
Marchand whistled a sizzler that caught Samsonov under the chin, momentarily stunning the saver.
Andrew Peeke, another playoff newbie, deposited Connor Dewar into the Boston net after the Maple Leaf forward gave Swayman a snow spray late in the period.
Toronto survived another power play (Tyler Bertuzzi high stick on Hampus Lindholm), as Pavel Zacha’s one-time rocket pinged off the crossbar.
Swayman came up with another dandy when an errant clearing pass landed on Auston Matthews’s stick, but the goalie gloved his pop shot.
Matching roughing penalties to Charlie McAvoy and Domi, followed shortly by a cross-check call on Lindholm gave the Maple Leafs a four-on-three advantage for the first 1:50 of the second.
When the Bruins killed it — thanks to yeoman’s work from Coyle and Brandon Carlo and two stunning Swayman pad saves on John Tavares — the crowd let them know how much they appreciated the work.
Boston’s first uh-oh moment came shortly after when Matthews sidestepped McAvoy and beat Swayman (who abandoned his fort) to a loose puck. The Toronto sniper had the whole net to shoot at, but his shot ticked off the far post.
“I thought it was 1-1,” said Montgomery.
Just 1:15 later, the Bruins doubled their lead from an unlikely source.
Carlo, who was enjoying a fine game on the back end, scored his first playoff goal since 2019 and the third of his career, bombing a rising clapper over Samsonov’s blocker.
Carlo got the puck after DeBrusk and Lindholm worked over Morgan Rielly behind the net, and DeBrusk hit Carlo on the tape.
“Jake had his eyes up and I could tell that we made eye contact and what a fantastic pass,” said Carlo. “And very fortunate to put that one in the back of the net.”
Matthews caught McAvoy with a high stick in front of Swayman, and the Bruins made the penalty hurt more than a stick to the chops.
DeBrusk circled from the top of the circle and ripped a wrister that Samsonov never saw to increase the lead to 3-0.
The Leafs didn’t learn their lesson as Domi slashed Marchand on the forearm off a faceoff and he was sent off.
DeBrusk struck for his second power-play strike when he parked himself in front of Samsonov and redirected a Marchand feed off the goalie, who made the initial save but couldn’t corral the puck as he stumbled backward into the net, giving the Bruins a 4-0 lead after two.
“Undisciplined,” Keefe said of Domi’s penalty.
David Kampf put the Leafs on the board at 1:39 of the third, but that was all they could muster against Swayman & Co.
Trent Frederic sealed it with an empty-netter.
Jim McBride can be reached at james.mcbride@globe.com. Follow him @globejimmcbride.