Evgenii Dadonov (2), Brady Tkachuk, Connor Brown, Alex Formenton and Drake Batherson scored for Ottawa (13-21-4) while Anton Forsberg stopped 35 shots. Montreal's (16-9-9) Josh Anderson (2) and Tyler Toffoli had goals as Carey price made 26 saves.
"I thought we played hard and well and played a team game out there," Forsberg said. "We threw pucks to net and scored a lot of goals which is always nice as a goalie."
The Senators needed just 42 seconds to open the scoring as after Josh Norris was high-sticked by Brendan Gallagher 28 seconds in, the power play got to work where Tkachuk got the puck down low and spun inwards to slide the puck under Price's right pad for his 12th of the year.
"That was a completely different hockey game than we played the other night," Tkachuk said. "Tonight, Saturday night, was a fun one to be a part of and was even better with the result we had
"Everybody was buzzing, everybody was going. Everybody had their 'A' game."
Montreal would get on the board themselves on a power play marker as Toffoli's quick release at 5:31 tied the game but the Senators re-took the lead down a man as Brown was on hand to bury Nicholas Paul's rebound at 12:07 for his second short-handed goal of the season.
Anderson knotted the game at 2-2 at 6:58 of the second with a wrister from the right faceoff circle as he buried his 12th goal of the campaign but the Sens grabbed the lead for the third time as Dadonov tipped in Thomas Chabot's shot 51 seconds later as he moved into double digits on the season.
"Playing with Formy and Arty was fun today," Dadonov said. "We scored three goals as a line. It was basically our first time on the ice together, all three of us, and I've played with Arty a lot before but with Formy, he's a good player with good speed."
Dadonov had his second of the night at 16:02 as his one-timer off of Artem Anisimov's pass from behind the net made it 4-2. Anderson's second of the game cut the deficit to one with 1:12 left in the period.
Formenton got his second goal of the season 2:55 into the third period as Anisimov's shot clipped the rookie forward to beat Price as the Sens pushed its lead to 5-3.
"We talked with Dadonov about how we're supposed to play the game and we tell Formenton too what we expect him to do on the ice and we just tried to find the open ice, make plays in the o-zone and it was clicking," Anisimov said. "It's always easier to play the game when you have a little bit of chemistry going."
Batherson scored into the empty-net with 2:55 left in regulation.
Eight of Dadonov's 11 goals this season have come on the road. In addition to Anisimov and Dadonov, Batherson and Thomas Chabot also had multi-point nights.
In his 50th career NHL game, Forsberg collected his first win in a Sens jersey.
Ottawa are back in action Monday when they visit Winnipeg.
