Jason Robertson had a goal and an assist, Jamie Benn and Roope Hintz each had two assists, and Jake Oettinger made 32 saves for Dallas (4-0-1).
"I think we understand what that team is over there," Pavelski said. "They have a lot of firepower. They're playing fast, they're playing with some confidence, so the challenge for us was, it's early, we've been playing good, don't take these guys light because they've put it on some teams early. If you mess around with the puck, they can turn and burn and get to you. And you saw that at times. When they had the momentum, they were coming.
"'Jakie' was solid, made all the saves, calmed it down a bit there, and I think our forecheck kind of took over the game there at times."
Arber Xhekaj scored his first NHL goal, and Jake Allen made 25 saves for Montreal (3-3-0), which had won its first three home games.
"It wasn't a consistent 60 minutes from our team," Canadiens forward Jonathan Drouin said. "They were consistent for 60 minutes and they won more battles."
Pavelski gave the Stars a 1-0 lead with a power-play goal at 4:24 of the first period. He had his back to the net when he took a pass from Benn and lifted a backhand over Allen.
"Those are the little things that he works on, and obviously he's getting pretty good at it," Benn said.
Mike Hoffman tied it 1-1 at 15:35 when he drove the net and scored on a rebound of Kirby Dach's shot.
Pavelski scored his second goal of the game 18 seconds into the second to put Dallas ahead 2-1, and Robertson extended the lead to 3-1 with a power-play goal at 4:31.