BOSTON - Eddie Lack has hardly looked like a backup goalie since Vancouver starter Ryan Miller was injured in a collision with a teammate.

Lack had 40 saves as the Canucks beat the struggling Boston Bruins 2-1 on Tuesday night.

"It was a busy night," Lack said. "It felt like we kept them a lot to the outside so it was a good overall effort from everyone."

Lack stopped 20 shots in the second period and 13 more in the third as Vancouver held on after Zack Kassian's tiebreaking goal at 6:47 of the third.

"He made some real big saves for us. It's good to see," Vancouver coach Willie Desjardins said. "You like to see a guy getting hot."

Especially right about now.

Lack replaced Miller early in the second period on Sunday at the New York Islanders after the Vancouver starter was injured in a collision. Lack made 27 saves while preserving the 4-0 shutout, then further frustrated the reeling Bruins in Boston.

"I always thought Eddie was good," Desjardins said. "He was so good the other night against the Islanders, he was unbelievable there and he just followed up again tonight."

Daniel Paille was the only player to beat Lack, scoring 1:05 into the game to give Boston a short-lived lead. Ryan Stanton scored for Vancouver 3:28 into the first to tie it at 1-all and Lack continued stopping a barrage of shots from the Bruins.

"We got some big saves from Eddie when we needed it and we capitalized on our chances," Kassian said.

Daniel and Henrik Sedin both picked up assists on Kassian's tiebreaking goal 6:47 into the third as the Canucks beat the Bruins for the second time this month.

Boston was coming off a 6-2 win at Chicago on Sunday to end a six-game winless streak. The Bruins played much of the final two periods in the Vancouver end, but could not beat Lack again.

"We've got to find a way to get a loose puck, or just a rebound, and find a way to score some more goals," Boston centre Patrice Bergeron said.

"He was square. He had a good night. I think we can be better with making it a little harder for him to see the puck. I thought we had some good chances, good shots, but not enough traffic."

Bergeron won 31 of the 38 faceoffs he took and Tuukka Rask finished with 26 saves for the Bruins, who are 1-6-2 in their past nine.

There were two quick goals, then the goalies took over for the rest of the first period and all of the second.

Lack faced three power plays in the second period, including one he created when he was called for tripping with 1:37 left. He stopped all 20 shots he faced in the period while Rask made 10 saves at the opposite end.

Kassian, who served Lack's penalty, broke the deadlock on a slap shot 6:47 into the third, getting assists from both Sedin brothers as the twins continued to pile up points lately. Henrik has nine points in the past five games and Daniel has seven — all assists — during the five-game stretch.

Notes: Claude Julien coached his 600th game for the Bruins. ... Lack was making his first career start against Boston. ... The Bruins have lost three straight at home. ... Vancouver was on the fourth of a five-game road trip, which wraps up Thursday at Buffalo.