BUFFALO — The Bruins made changes after Wednesday’s debacle. How could they not?

But if you expected Bruce Cassidy to go wholesale, you would be underselling the talent on his roster. You would also be overreacting to one game, albeit a very poor one.

Cassidy juggled a few forwards, mostly ones with inexperience in his system, but kept his top line together, his power play intact, his regular defensemen paired. If the Bruins were to climb out of the crater created by the Capitals, they needed their best players to be, well, at their best.

Some people, you can count on.


“When you have a game like [Wednesday] night, it can definitely make you a little nervous on how things are going to go,” said Brad Marchand, who tied a career high with four assists in Thursday night’s 4-0 win over the Sabres. “I think this gave us the confidence that we can settle down and bounce back.”

Marchand helped familiar names score — Zdeno Chara, Ryan Donato, David Pastrnak, and Patrice Bergeron — and Boston rebounded from a 7-0 whipping in Washington with a shutout victory at KeyBank Center. Behind those players and backup goalie Jaroslav Halak (32 saves), they played spoiler during a home opener for a change.

It was Buffalo’s night, but it quickly became Boston’s.

Like the Stanley Cup champs, the Sabres had something to celebrate: the debut of No. 1 overall pick Rasmus Dahlin, the smooth-skating, physical, would-be franchise defenseman; Jack Eichel’s first night as captain; new additions Conor Sheary, Jeff Skinner, and Carter Hutton; and a Lake Erie-sized reservoir of hope.

They were booing extra hard after the announcement of Boston’s first goal of the season, at 6:33 of the first period. They heard the name of Chara, the goal scorer, who walked in and zipped it past Hutton, and shouted. They heard that of Marchand, who assisted with a pull-up, curl, cross-ice feed, and jeered harder. Charlie McAvoy, who had the secondary assist, got a low grumble.


Pastrnak was on fire, even before he was rewarded with a layup goal. The No. 1 right wing, dangerous with the puck all night, did not record an assist on the scoresheet. He did have two of the tertiary variety. Before Chara’s goal, he dived in the slot to break up a scoring chance. On the Bruins’ 2-0 tally, Pastrnak circled the entire offensive zone and drew a slashing penalty.

On a power-play rush, Bergeron hit Marchand over the line. He froze defenseman Rasmus Ristolainen and Hutton with a deke, and found a streaking Donato for a right-side tap-in at 15:34 of the first.

Sabres fans, hardly showing patience, scattered boos at their team after a 2-0 first period.

“You could sense the fans were waiting for that goal,” Chara said. “We didn’t let them have it. We kept it pretty quiet for most of the night.”

Pastrnak’s official point, at 16:16 of the second, was a gimme. Marchand, strong on the forecheck, controlled and found David Krejci, who was on for a line change. A slick cross-ice dish, one that squirted through Dahlin, and Pastrnak swept in his first of the season.

Halak, late of the sub-.500 Islanders, was rock-solid in his first Boston start. When the Bruins’ coverage broke down, which it did more often when they built the three-goal lead, Halak looked like a former No. 1.


“We had a pretty good game,” Marchand said. “We didn’t have a great third, but Jaro shut the door.”

Cassidy said he and the staff attacked puck management and battle level in the morning meetings. In the pregame session, it was about systems, theirs and Buffalo’s. “They get a little slap in the morning and a little love in the evening,” said Cassidy, who gave new third-line center Sean Kuraly a boost of speed on the wings (Danton Heinen on the left side, the returning Anders Bjork on the right), promoted Donato to Krejci’s right flank, dropped David Backes to the fourth line, and scratched Chris Wagner.

The Bruins’ coverage was tighter and more aggressive than Wednesday. If they turned the puck over, they snuffed it out. The Sabres, who look to be more skilled than recent editions, were throwing passes into Boston sticks far too often.

“We were just brutal everywhere [Wednesday],” Marchand said. “I don’t think we needed film to know that. We knew we just had to compete harder, come back harder, and win more puck battles.”

Instead of Cassidy yanking his goalie, it was Sabres coach Phil Housley pulling Hutton for an extra man at 14:57 of the third. Given all that man-up time, his team managed two shots on net before a timeout with 1:23 left. They went on a six-on-four power play with 38.8 seconds left, and Bergeron cashed in the shorthanded empty-netter with 12 seconds to go — a feel-good goal given Bergeron’s health issues this offseason.


“Tonight he took a good step forward,” Cassidy said. “He just needs his reps . . . I’m not worried about Bergy at all.”

It really was Boston’s night: After Pastrnak’s 3-0 goal, McAvoy limped off after blocking a slapper from Nathan Beaulieu, apparently off the inside of his left skate. He went to the dressing room and missed the remainder of the second period.

But he was back out for the third, working the puck into high-danger situations, and readily joining the attack. Like so many teammates, looking much better than his season debut.

And ready to please in Boston’s home opener, a 1 o’clock matinee Monday against Ottawa.

“It’s what have you done for me lately sometimes,” Cassidy mused. “We’re going to go home, we’re going to be a team that’s 1-1, which isn’t terrible . . . It should carry over to Monday, that defensive effort. It’s a good learning lesson for all the guys.”

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