BOSTON -- That huge sigh of relief you might have heard came from the Boston Bruins dressing room after the team discovered its power play Monday night.

It was only one game, but the Bruins doubled their power-play goal total of the first 11 games, scoring three times in front of Tuukka Rask's shutout goaltending in a 4-0 victory over the Buffalo Sabres.

The Bruins came into the game 3-for-38 on the power play and having allowed as many short-handed goals, went 3-for-8 with the advantage in this game.

"That was a big power-play night for us," said David Krejci, who finally scored his first goal of the season and did it with the Bruins having a two-man advantage. "Hopefully we've got some more in the bag, especially for tomorrow (in Montreal)."

Riley Nash also scored his first goal of the season, and Rask made 32 saves for his 32nd career shutout as the Bruins presented coach Claude Julien with his 400th victory behind the Boston bench.

"Another number. I move on from those," Julien said. "Like I always say, it's something I can cherish down the road. Right now, I've just got to keep plugging away."

It was a big relief for him to see Krejci finally score. The center had four assists but couldn't find the net until his one-time slapper beat goalie Robin Lehner.

"When you're known to be a guy that can produce and get points, it's nice to get that first one in game number 12," Julien said. "Hopefully he can build on that, gain some confidence or whatever, some mojo that's needed to help us out that way.

"When he's on his game, he's one of the most dangerous players on our team."

Boston, playing two nights after allowing two short-handed goals to the New York Rangers, got power-play tallies from Brad Marchand, Krejci and David Pastrnak.

Marchand's fifth goal of the season opened the scoring at 5:44 of the second period. Krejci made it 2-0 at 10:12 of the middle period, and Nash scored his first goal as a Bruin at 14:41, getting a sharp-angle shot past Lehner at even strength.

Pastrnak, who also had an assist, scored his eighth goal of the season 9:45 into the third.

Rask, who was shaky in the 5-2 loss to the Rangers, was sharp Monday, when he stopped 14 shots in the third period. The Bruins improved to 9-1-2 in their past 12 games against the Sabres -- including 5-1-2 in the past eight home contests vs. Buffalo. It was Rask's second shutout of the season as he raised his record to 7-1-0.

With the game at Montreal on Tuesday night and Rask playing with some sort of lower-body issue, it appears rookie Zane McIntyre could be headed for his second NHL start.

"It's not mine," Rask said of the decision. "I don't know. But it's one of those games that I don't think any player really wants to miss because it's a big rivalry and they're a great team. So definitely don't want to miss that, but we'll see."

Rask is 5-15-3 with a 2.69 goals against average and .909 save percentage lifetime against the Canadiens.

In addition to the first goals of the year for the two Bruins, Matt Beleskey had an assist on the first goal, his first point of the season.

The win was only the second in five home games for the Bruins (7-5-0) this season. Boston missed the playoffs for a second straight campaign in April primarily because of a 17-18-6 home record.

The loss was only the second in regulation for the Sabres (5-5-2) on the road, where they fell to 4-2-2.

Speaking about the penalties, Brian Gionta, who had his short-handed breakaway stopped by Rask in the second period, said, "It gets you out of your rhythm. Obviously it gives them momentum, but the biggest thing is you're overtaxing your killers and not getting a good rotation when the guys are sitting down.

"We've got to keep our cool -- no matter what's going on out there. You've got to stay composed, whether you're mad at it or not and don't agree with it."

Lehner played well, making 38 saves, but fell to 3-7-3 lifetime against the Bruins.

NOTES: LW Tyler Ennis and D Dmitry Kulikov, who missed the Sabres' skate at the Bruins' new practice facility Monday, were both in the lineup Monday night. Buffalo was without three mainstays, C Jack Eichel, LW Evander Kane and D Zach Bogosian, due to injuries. ... The Bruins have five games in seven days this week ... The Sabres host the Ottawa Senators on Wednesday night -- four nights after beating the Senators 2-1 in Ottawa.