Newhook extended the lead to 2-0 at 7:50, skating into a pass from Cogliano and scoring with a slap shot from the top of the left circle.
"I think it was a great play by [O'Connor] and 'Cogs' to check the puck back there," Newhook said. "That was a big emphasis for us, to forecheck, and they did. I was just trying to come in late, be an option, and 'Cogs' made a great pass to me, and I just tried to put it in the net."
Lehkonen pushed it to 3-0 at 9:05 of the second period when he warded off Senators defenseman Jake Sanderson on a partial breakaway and scored with a backhand in tight.
"The pretty stuff doesn't ever work unless your compete level's high," Bednar said. "When you see a pretty goal, it's usually because a couple other guys on the ice were doing some heavy lifting, winning a battle, winning a race, and making a firm puck play into the right area of the ice."
Rantanen made it 4-0 at 15:57 with a shot from the left circle that went under Forsberg's right pad. It was his fifth goal in his past six games.
"Really determined player. Wants to make an impact every night and has made an impact on basically every night," Bednar said. "Just trying to push himself to another level, the next level. He knows our team needs it. I just see a highly determined player in all areas of his game."
Lehkonen scored a power-play goal to make it 5-0 at 8:18 of the third period. He received a backhand pass from Nathan MacKinnon all alone in front and finished with a backhand with his back turned to Forsberg.