After signing a one-year contract extension earlier today, Anton Forsberg made 30 saves for the Senators (21-27-5) while Shane Pinto, Brady Tkachuk, Nicholas Paul, Connor Brown and Alex Formenton scored. Montreal's (24-19-9) Jake Allen turned away 29 shots while Joel Edmundson had their only goal.
"We played a hard game and played within our structure," Forsberg said. "We created a lot of scoring chances with a good forecheck and putting pucks deep and I thought we played a solid game out there."
It was Pinto who opened the scoring and he did so by burying the first goal of his NHL career. Artem Zub's initial low shot was saved by the right pad of Allen but Pinto was on hand to bang the rebound in at 11:35 for his first pro goal.
"It was good to get the first one out of the way but I'm just happy we won," Pinto said. "I thought we played pretty well and to contribute to that is obviously really cool."
Montreal tied the game with 32 seconds left in the first off of a set play off a faceoff as Edmundson found himself in the slot to score his third goal of the season.
Ottawa re-took the lead 3:44 into the second as Josh Norris stuck with the puck on a battle behind the net and then centered out front to Tkachuk who'd bury his 17th of the year for a 2-1 lead.
The Sens made it a 3-1 game with 7.5 seconds left in the frame as Paul got the slightest touch on Erik Brannstrom's point shot to grab his fifth of the campaign.
Brown pushed the lead to 4-1 at 4:40 of the final period as he buried a one-timer off of Zub's cross-ice feed for his 19th goal before Formenton added another with a burst of speed down the right wing before flipping the puck high over Allen's glove for his fourth of the season at 10:19.
Sens defenceman Olle Alsing made his NHL debut playing 12:05 while Vitaly Abramov made his season debut after entering the lineup just before warmups in place of fellow Russian Evgenii Dadonov and logged 9:38 of ice time. Jacob Bernard-Docker played his second NHL game, paired with Alsing, three weeks after making his debut.
"When you're getting in there for your first game, or first couple of games, you're dealing with guys that have played all year," Sens head coach D.J. Smith said. "It's a learning experience for everyone. It's so much easier when you get in and get to play with an older player but when you're that young back there, everyone's got to play and it's trial by fire and they'll get better as we go."
Brannstrom had three assists tonight, his first career multi-point game in the NHL, while Artem Zub had a pair of assists to record his first multi-assist game with the Senators.
The Sens are back in action Saturday when they open a two-game road trip by visiting Winnipeg.