NEW YORK -- Shea Weber scored a power-play goal with 2:57 remaining in the third period to give the Montreal Canadiens a 3-2 win against the New York Islanders at Barclays Center on Wednesday.
Weber scored 55 seconds after Islanders defenseman Nick Leddy was called for slashing, one-timing a pass from defenseman Jeff Petry over the right shoulder of goalie Thomas Greiss.
"We got our one opportunity tonight and we were able to get the goal at the big moment in the game," Weber said. "The power play should be a difference-maker, the penalty kill the same thing. You've got to be able to win your team games at times, and tonight we were able to do that."
Montreal (6-0-1) is the only NHL team without a regulation loss.
"He just shot a nice knuckle puck top shelf," Greiss said.
The Canadiens twice had a one-goal lead but the Islanders tied the game each time. It was 1-1 heading into the third period when Canadiens forward Phillip Danault put a loose puck past Greiss at 11:21 to give Montreal a 2-1 lead. New York defenseman Dennis Seidenberg tied the game 2-2 at 14:16.
Video: MTL@NYI: Danault jams a rebound home past Greiss
Weber assisted on Danault's goal and has three goals and nine points.
"Shea was phenomenal again. He scored with a great shot," Canadiens coach Michel Therrien said. "What I'm the most impressed about is his defensive game. Yes, he can shoot the puck and is good on the power play, but you look at his defensive game and he is a tough guy to play against. We like what we've seen from him since the beginning of the year."
Montreal goalie Al Montoya made 26 saves and is 3-0-1. He played two seasons with New York from 2010-12, including an NHL career high 26 starts in 2011-12.
"It was a road game," Montoya said. "We came in here and battled and got the two points we needed. It's a long season and we don't kid ourselves. We try to win the next one. This is going to feel good and we will enjoy it for a little bit but we have [the Tampa Bay Lightning] tomorrow."
Montoya has made it easier for Therrien to limit the workload of Carey Price, who has won his three starts.
"[Montoya has] played really well," Therrien said. "He's giving us a chance to win hockey games, it's pretty simple."
Paul Byron gave the Canadiens a 1-0 lead 3:10 into in the second period. The Islanders (3-4-0) tied the game 1-1 when John Tavares scored his fourth goal of the season, on a power play at 15:17 of the second after Canadiens defenseman Alexei Emelin failed to clear the puck in front of Montoya.
Video: MTL@NYI: Byron bangs home rebound to open the scoring
Greiss made 26 saves, including 11 in the second period.
"The second period was probably our worst period of the season, but we responded in the third with a better effort and gave ourselves a chance," Tavares said. "We just didn't get it done"
Goal of the game
Tied 2-2 late in the third period, Canadiens captain Max Pacioretty passed the puck down to Petry at the blue line. Petry passed to his left to Weber, who one-timed the puck top shelf.
Video: MTL@NYI: Habs take lead on Weber's PPG late in 3rd
Saves of the game
With the Canadiens leading 2-1 in the third period, Montoya made three saves in a 27-second span on shots by Johnny Boychuk, Anthony Beauvillier and Boychuk again. Montoya was then unable to cover the puck, which went to Beauvillier in front, but the goalie appeared to get his pad on the point-blank shot at 6:20.
Unsung moment of the game
Weber had a Canadiens-high four blocks, including one on a Thomas Hickey shot with 28 seconds left.
Highlight of the game
Tavares tied the game in the second period by placing a perfect shot past Montoya. With New York on a power play, Tavares grabbed a rebound, used teammate Andrew Ladd as a screen, and shot the puck between Ladd's legs and into the near right post.
Video: MTL@NYI: Tavares jumps on a rebound, scores PPG
They said it
"Are you kidding me? Even when he is generous with it, it still hurts [in practice]." -- Canadiens goalie Al Montoya on Shea Weber's slap shot
"He's the reason why we had a chance to win tonight, bottom line." -- Islanders captain John Tavares on goalie Thomas Greiss
Need to know
Weber (three goals, four assists) extended his point streak to four games. He was plus-2 and is plus-12 this season. ... The power-play goal allowed by the Islanders was their second of the season (21-of-23 kills). ... Tavares has four goals in five games. … Islanders forward Nikolay Kulemin did not play and is day to day with an upper-body injury. He was replaced by rookie Mathew Barzal, who played 9:20 in his second NHL game.
Canadiens: At the Tampa Bay Lightning on Thursday (7:30 p.m. ET; SUN, RDS, SN360, NHL.TV)
Islanders: At the Pittsburgh Penguins on Thursday (7 p.m. ET; MSG+, ROOT, NHL.TV)
Video: Weber's late PPG lifts Canadiens over Islanders, 3-2