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 was waiting for this game,” Canadiens coach Martin St. Louis said. “And they were just playing 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 tied 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 with a tap-in at the left post off a seam pass from Guhle at the right point.
Kastelic tied 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 marked Lindholm’s first goal for Boston -- and Zadorov’s second assist -- after each signed long-term contracts with the Bruins when free agency opened on July 1.
“I was just trying to open myself up in the high slot, and obviously we had eye contact there, so I kind of knew [Zadorov] was trying to go for [a] shot-pass there,” Lindholm said. “So, it was a great play by 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 it to 5-2 at 16:51 when he stuffed in Beecher’s net-front 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 structure-wise, we can’t make those mistakes. So yeah, [we] dug ourselves too big a hole.”