The Canadiens (26-11-2) became the third team in the past two days to hold first place in the Eastern Conference. The Tampa Bay Lightning began Friday in first before losing 6-3 to the Penguins, whom Montreal overtook with its win Saturday.
"We're in a position to win five games in a row on the road and our guys showed a lot of energy tonight," Canadiens coach Michel Therrien said. "They concentrated on the detail of the game and that was a huge challenge. We did a good job."
Alexei Emelin's slap shot hit the right post behind goalie Marc-Andre Fleury and went into the net to put the Canadiens up by three with 5:52 remaining in the third period. It was Emelin's first goal since March 24 of last season against the Boston Bruins.
Montreal has won eight of its past nine games and two in the past two days. Price made 30 saves one night after his 4-2 win at the New Jersey Devils on Friday.
"Guys are playing good hockey," Price said. "Everybody's contributing, everybody's working, everybody's doing whatever they need to do to help the team be successful, and it's really fun to be a part of."
Pittsburgh (24-10-5) failed to carry the momentum of two consecutive wins following a four-game losing streak. The Penguins haven't scored more than two goals in four of their past five games.
"Just on the game, in the first period, I thought we had a good first period," Penguins coach Mike Johnston said. "The second period … I thought they stood us up at the line. We didn't get pucks in behind them. We couldn't make plays through traffic or make the quick play in the neutral zone to get around people. We didn't get a lot of support.
"They did clog it up, but I also thought it was more on our side too, with our execution. I didn't think our execution was very sharp."
Montreal took a 2-0 lead that was initiated by Max Pacioretty 2:30 into the first period. Tom Gilbert sent a shot into the Penguins crease, and Pacioretty whiffed on an attempted rebound before connecting on a second attempt to put a snap shot past Fleury for his team-leading 16th goal.
"Two times they go to the net," Fleury said. "The last goal, I couldn't see much of, and I think that's how they play. They shoot pucks and guys get some traffic and it worked out all right for them. … The second one, I just didn't see the release and it just went through a [defenseman], and I wish I could've stopped that one.
"It's tough. We dug ourselves a little hole there and they closed the game pretty well and we didn't get too much after."
Pittsburgh controlled the remainder of the first period and was sparked when David Perron scored his first goal with the Penguins at 9:59. Sidney Crosby fed a pass to Perron at the edge of the left faceoff circle, and his wrist shot into the left side of the net went past a lunging Price.
The Penguins acquired Perron from the Edmonton Oilers on Friday in a trade for a first-round pick in the 2015 NHL Draft and forward Rob Klinkhammer. Perron played alongside center Crosby and right wing Steve Downie.
"I think, obviously, with the past couple days here, the energy wasn't as good as I wanted it to be, but I was running on adrenaline and trying to push myself as much as possible," Perron said. "Just didn't have enough tonight, but it was definitely good to get with the guys in the first game, and I'm looking forward to build with them here."
Gilbert re-established Montreal's two-goal lead early in the second period. P.K. Subban sent a pass to Pacioretty, who charged down the right boards before sending a pass at the blue line to Gilbert alone on the left side of the ice. Gilbert's wrist shot avoided Fleury's blocker to put the Canadiens up 3-1, 1:49 into the second.
Montreal had 11 of the period's first 12 shots.
"We knew this was going to be a tough road trip, especially after a bit of a little bit of a break, and to be honest, I think we've been playing our best hockey and been doing really good things with the puck," Gilbert said. "We've been keeping it simple, especially on the road here, and that's been our biggest success, and, obviously, our best players have been our goalies. That's always huge."