BOSTON -- David Pastrnak had a goal and two assists just a few hours after signing a new contract, and the surging Boston Bruins became the fastest team in NHL history to reach 100 points by beating the Buffalo Sabres 7-1 on Thursday night.

Jakub Lauko scored twice, Dmitry Orlov added a goal and two assists, and Jeremy Swayman stopped 26 shots as the Bruins overcame the loss of Brad Marchand to a lower body injury to win their ninth straight.

Boston improved to 48-8-5 in its 61st game, besting the Montreal team from 1976-77 that reached 100 points in 62 games when there were regulation ties and no extra points for overtime or shootout victories. The Bruins have seven points for overtime and shootout victories in their 101 points.

Pavel Zacha, Patrice Bergeron and Connor Clifton added goals for Boston.

"It's been really amazing to watch them want to be great," coach Jim Montgomery said.

Casey Mittelstadt scored for Buffalo, and Ukko-Pekka Luukkonen stopped 35 shots. But his unusual tripping penalty led to Orlov's power-play goal and turned the game as the Sabres dropped their second straight.

The victory capped an eventful day for the Bruins. They acquired Tyler Bertuzzi from Detroit and inked Pastrnak to an eight-year, $90 million extension.

"Probably took a little longer than we hoped for, but we finally got across the finish line," Boston president Cam Neely said. "We're thrilled to have him for another eight years."

Pastrnak drew the odd penalty against Luukkonen in the second period and then assisted on the ensuing goal. He scored his 43rd goal into an empty net in Boston's five-goal third period that also saw him earn his 40th assist.

Bertuzzi, called a good "sandpaper" guy by Montgomery, will help fill the roles of fellow wingers Taylor Hall and Nick Foligno. Hall was placed on long-term injured reserve and Foligno regular IR.

Last week, GM Don Sweeney picked up Orlov and Garnet Hathaway in a deal with Washington. Orlov has three goals and five assists in four games since the trade.

A lengthy absence by Marchand would hurt Boston, however. He took a big hit in the second period and didn't return for the third.

"We think he's going to be all right," Montgomery said.

The Sabres, who lost top-line forward Alex Tuch (lower body) last week, again played without banged-up top defenseman Rasmus Dahlin. He was placed on injured reserve, retroactive to Friday, opening a roster spot for defenseman Riley Stillman, acquired Monday from Vancouver.

Stillman made an immediate impression, recording five hits in a scoreless first period.

And it remained deadlocked until Luukkonen was called for tripping as Pastrnak tried to beat him while skating in alone.

"It was an unfortunate call," coach Dan Granato said. "Obviously, the referees thought it was a trip. Luukky came out and played the puck, but that's what happens. You're going to have challenges like that, but obviously it was a momentum swing."

Orlov scored on a one-timer on the ensuing 4-on-3, and Lauko knocked in a fat rebound 1:26 later to make it 2-0.

Buffalo, in a scramble for one of the last playoff spots in the Eastern Conference, couldn't recover.