The Bruins took a simple approach to their season opener, and that was enough to seize a victory

Entering Saturday’s season opener, the Bruins were on a nine-day break since their preseason finale, a layoff that threatened to make minds and sticks dull.

Their opponent, Dallas, is known for locking down the defensive zone. It was also difficult to ignore how much career success the visiting netminder, Braden Holtby, has had against Boston.

So the Bruins’ first win of the year, a 3-1 decision over the Stars, was nothing fancy. They skated hard, won puck races, and cashed in when they could.

“Just simple hockey this time of year,” coach Bruce Cassidy said. “Speed and tenacity.”

Brad Marchand scored twice, once on a penalty shot and once into an empty net in the final minutes. Jake DeBrusk, starting what everyone in Black and Gold hopes will be a monster comeback season, gave the Bruins the lead in the third period by jamming home a loose puck.

Rookie Jeremy Swayman, starting his 11th career game (not including one in last year’s second round against the Islanders), stopped 24 of 25 shots. The Alaskan was beaten on one of the Bruins’ lone gaffes, a too-long shift in the second period that saw a wide-open Luke Glendening score from the slot.

Other than that, and a bit of early-season sloppiness that put them on the penalty kill six times (6 for 6), Cassidy likely didn’t have too much to fret over. The Bruins landed 40 of 63 attempts on Holtby (37 saves), who all but owned the Bruins during his days as a Capital. He was plenty good enough to win Saturday.

Dallas didn’t allow regular entry to the middle of the ice, but DeBrusk made good early in the second, after winning a footrace to a puck in the offensive zone. Speedy newcomer Erik Haula picked up the biscuit and made a centering feed to Nick Foligno, and DeBrusk was there when the high-speed pass bounced off the winger.

DeBrusk had a good camp, and carried that over to Saturday. Cassidy noted how he “got lost in the second period with some of the penalty kills,” he said. “He kept his feet and stayed in the game. That’s a sign of being a good pro. Some maturity there. As a result, I tried to get their line involved a little more in the third.”

The Garden was rocking, as expected, for the first season opener at home since 2017. Marchand made the place explode with 2:22 left in the first, converting a penalty shot for the first Boston goal of 2021-22. Winding up from deep in his zone, he collected the puck with speed and beat Holtby blocker side from between the hashes.

The chatter on the bench, DeBrusk said, was Marchand would deke. “I thought he was going five-hole,” he said. “I thought he was going backhand, five-hole.”

Marchand made the call at the last second.

Bruins right wing David Pastrnak takes a heavy hit from Dallas Stars defenseman Jani Hakanpaa during the third period. Barry Chin/Globe Staff

“The only thing I was thinking was don’t miss it,” said Marchand, who notably whiffed on a deciding shootout attempt against Philadelphia in March 2020, leaving the puck at center ice.

“That’s a lot of pressure in the home opener,” DeBrusk said. “I think we can all agree we were happy it was on Marchy’s stick.”

The newly minted alternate captain earned the penalty shot after picking off a Roope Hintz outlet outside the blue line, pausing his reload just long enough for David Pastrnak to tag up. He broke for the slot, where Ryan Suter held his stick.

Simple, hard, intelligent hockey, the kind that starts the season off right. The summer drags on, and training camp drags on.

“It almost felt like you had to go through summer twice,” Marchand said. “It dragged on. We always get excited to get back and see the team we have, and be in front of a crowd again. It’s a lot more normal this year. A little nerve-wracking. Had butterflies. It was fun.”

Through 40 minutes, the Bruins were hammering the Stars in shots (28-14), but one poor shift had the game tied at 1.

Boston’s second line coughed up the equalizer at 9:15 of the second, after soft plays had them out there for a 1-minute, 34-second shift. Not enough juice from Taylor Hall, Craig Smith, and Charlie Coyle, who couldn’t clear the zone against the Stars’ fourth line. After Smith couldn’t bank a pass out of the zone, Tanner Kero beat Hall’s check and fed an unmarked Glendening, who had time to load up and beat Swayman from the slot.

“Kind of triplicated there,” Cassidy said of the defensive coverage, which left Glendening loose. “Guys got a little fatigued.”

Swayman, who improved to 5-0-0 with a .953 save percentage at TD Garden, didn’t worry much.

“I typically scan it and forget about it,” he said. “When it goes in, you know what you did wrong right away, and focus on the next shot.” .

He was upbeat afterward, grinning and soaking in “the magnitude” of becoming the first rookie netminder to start a Bruins season opener since Blaine Lacher in 1995.

“He was good. He got beat on a clean shot,” Cassidy said. “After that he looked rock-solid.

“Good for him. He’s done it for us almost every time he’s played. It’s almost like we’re coming to expect that, and that’s a good thing.”

Matt Porter can be reached at matthew.porter@globe.com. Follow him @mattyports.