O’Connor has scored in each of the past two games following a 10-game drought.
“He’s been playing phenomenal,” Rust said of O’Connor. “He’s been skating really, really well. He’s in on the forecheck, causing turnovers. An unbelievable shot on his goal tonight. He’s playing with a lot of confidence. We’re going to need more of that out of him. He’s been fantastic.”
Letang scored an empty-net goal from the other end of the ice with 1:25 remaining for the 4-1 final.
The Canadiens were 0-for-3 on the power play, including 0-for-2 in the third.
"I thought the special (teams) unit did the job, so we didn't give them a power-play goal,” Letang said. “Power play got us a big one. ‘Jars’ has been really good since the beginning of the year. ... Tonight, I think it represented the game pretty much.
"It's a loose team on the other side. They have a lot of creativity. They play with some swag and it's tough to read, so to have a good defensive posture all game was key."
Montreal forward Colin White had one shot on goal in 11:11 of ice time after being claimed off waivers from Pittsburgh on Thursday. White, who played 11 games for the Penguins this season, participated in their optional morning skate.
"Yeah, it's pretty crazy,” White said. “A lot of those guys waking up from naps were like, 'What the heck is going on, we're playing you now?’ Those are great guys. And the team here took me in real well so far, so it's really exciting.”
NOTES: During the game, the Penguins acquired forward Emil Bemstrom in a trade from the Columbus Blue Jackets for forward Alex Nylander and a conditional sixth-round pick in the 2026 NHL Draft. Bemstrom, 24, has 11 points (five goals, six assists) in 32 games this season. ... Penguins forward Noel Acciari had one shot on goal and two hits in 15:10 in his return after missing six games with a concussion.