Brendan Gallagher scored twice, and Joel Armia, Lane Hutson and Kaiden Guhle each had two assists for Montreal (1-1-0). Cayden Primeau made 23 saves and Oliver Kapanen had an assist in his NHL debut.

“This is a team that has been waiting for this game,” Canadiens coach Martin St. Louis said. “And they just played it simple, better than us tonight for 60 minutes. We had moments, but it wasn’t enough.”

Gallagher gave the Canadiens a 1-0 lead at 8:26 of the first period with a power-play goal, redirecting Armia’s shot from the top of the left circle past Swayman.

Charlie McAvoy made it 1-1 at 11:04 with a wrist shot from the high slot on the power play.

Cole Caufield put Montreal ahead 2-1 at 12:18, tapping the puck in at the left post after a seam pass from Guhle at the right point.

Kastelic made it 2-2 at 13:24 with a wrist shot from the top of the left circle.

Lindholm gave the Bruins a 3-2 lead at 18:23, redirecting Zadorov’s shot from the point past Primeau. It was Lindholm’s first goal for Boston and Zadorov’s second assist after they both signed long-term contracts with the Bruins when free agency opened on July 1.

“I was just trying to get myself open in the high slot, and obviously we had eye contact there, so I kind of knew (Zadorov) was trying to make a shot pass there,” Lindholm said. “So it was a great play from him, a heads-up play, and yeah, it was nice to see it go in.”

Pastrnak made it 4-2 at 15:56 of the second period with a one-timer from the slot, and Koepke pushed the score to 5-2 at 16:51 when he stopped Beecher’s net attempt.

“We kind of shot ourselves in the foot there in the second,” Canadiens captain Nick Suzuki said. “We give up a few goals that we definitely want back, and structurally we are not allowed to make those mistakes. So yeah, (we) dug too big of a hole for ourselves.”