Confident, loose, sometimes bold on the attack, the Bruins on Saturday improved to 2-0 in the Butch Cassidy coaching era, rubbing out the visiting Canucks, 4-3, with David Pastrnak’s game-breaker with two minutes remaining in regulation.

Nothing begets smiles like winning, especially for a team that has spent most of 2016-17 struggling to score goals and struggling even more to put together a winning streak. Suddenly the Bruins are demonstrating some pluck, on the heels of longtime coach Claude Julien being dismissed Tuesday and replaced by the more aggressive, offensive-focused Cassidy.

Pastrnak, fed a long diagonal pass through the neutral zone by linemate David Krejc­i, raced over the blue line at left wing, and snapped the winner by Canucks goalie Ryan Miller less than four minutes after the Canucks pulled into a 3-3 tie.

No overtime necessary. No flip-of-the-coin shootout. The sellout crowd of 17,565 at TD Garden danced out onto Causeway Street, the Bruins back on the right side of .500 (14-13-0) on home ice this season.

“He found me there,’’ said Pastrnak, referring to Krejci’s bow-and-arrow feed through the neutral zone. “I tried to cut into the middle and just throw into the net and it went in.’’

The goal moved Pastrnak into the team lead for goal-scoring (25) and it also provided the winning cushion for backup goalie Anton Khudobin, who snuffed out 29 shots in his first start since Dec. 23.

Other than lack of scoring, backup goaltending has been a festering wound for the Bruins this season, with Khudobin yo-yoing back and forth between Boston and AHL Providence amid management’s search to provide No. 1 Tuukka Rask with adequate support.

“Of course, you don’t want to be back and forth,’’ said Khudobin, a locker room favorite, who improved his record to 2-5-1 (to Rask’s 26-13-4). “But it is what it is. I have to find my game, do whatever it takes to stay here. I’m happy with the win. It’s good for me and it’s good for the team.’’

The victory also helped the Bruins keep their ever-so-tenuous hold on a playoff spot in the Eastern Conference, a grip that slipped the previous Saturday in a wild 6-5 loss to Toronto that ended up being Julien’s last game behind the bench. They entered Saturday’s game in possession of one of the conference’s two wild-card spots. It was the hope of avoiding a third straight postseason DNQ that led GM Don Sweeney and team president Cam Neely to turn over the team to Cassidy.

It was also a successful afternoon for ex-UMass standout Frank Vatrano, who scored once, had two assists, and cobbled together his first 3-point performance of the season.

Vatrano helped on the first Boston goal by Kevan Miller, pulling the Bruins into a 1-1 tie at 13:33 of the first. He then nailed home the go-ahead goal, 2-1, ripping home a close-range shot from the right side on Krejci’s pinpoint feed on the power play. He also cut off a Canucks attempt to get out of the defensive zone in the third, throwing a pass to Jimmy Hayes that ultimately led to Colin Miller smoking in the go-ahead goal, 3-2, with only 2:12 gone. Even Hayes, a buyout-in-the-making this season, looked good.

“Jimmy did a great job there,’’ said Colin Miller, who stepped into a one-time bomb for his fourth goal this season. “He put in a tee and I closed my eyes.’’

The Canucks, their season headed straight to a playoff DNQ, pulled even, 3-3, on a power play with 5:37 left in regulation. The refs made the wrong call on Tim Schaller, sending the Boston winger to the penalty box for a broken stick they mistakenly called a slash, and it was Markus Granlund who cashed from the slot on an Alex Edler feed.

But only 3:37 later, Krejci detecting a wide seam in the Canucks’ neutral-zone coverage, lasered his home run pass to the galloping Pastrnak. Twice burned on turnovers earlier in the afternoon, the Czech winger drove in his fifth goal in the last three games.

“Well, that’s David, right?’’ said Cassidy, noting Krejci’s handiwork in setting up Pastrnak. “He makes plays and we are going to keep encouraging him to make plays.’’

The defense-first mantra of Julien, which helped lead the Bruins to a Cup win over Vancouver in 2011, isn’t completely gone. But in the Black-and-Gold world of Coach Cassidy, defense is assumed, and offense is the giant block of clay, awaiting anyone’s hands for creative molding.

If they mess up, try again. There is always more clay until the clock reads 0:00.

“I’m glad to see him get rewarded for the plays he did make tonight,’’ said Cassidy, again dwelling on Krejci, whom he’ll need to be a key contributor night after night. “We’ll build in some shooting mentality, too, in that line [with rookie Peter Cehlarik and Pastrnak], so they’re not one dimensional. He’s got a terrific shot and we’re going to encourage him to use it.’’

Kevin Paul Dupont can be reached at kevin.dupont@globe.com. Follow him on Twitter @GlobeKPD.