Matt Bartkowski, with a goal and an assist for the first three-point game of his career, and Emerson Etem, with two, also scored for Vancouver (24-24-12). Ryan Miller made 27 saves, while Virtanen added an assist. Linden Vey also had two assists.
Mike Hoffman, Mark Stone and Bobby Ryan replied for Ottawa (29-27-6), while Dion Phaneuf and Jean-Gabriel Pageau each chipped in with two assists. Craig Anderson made 31 stops for the Senators, who saw a four-game winning streak come to an end.
Vancouver snapped a four-game losing streak with a 5-1 home win over the Colorado Avalanche on Sunday, but still sit eight points back of a playoff spot.
Ottawa, meanwhile, is looking to make another late charge into the post-season after finishing the 2014-15 campaign on an improbable 24-4-4 run to grab a wild-card spot in the Eastern Conference.
The Senators sit four points back of Pittsburgh for the second wild-card spot in the East, although the Penguins have three games in hand.
Trailing 3-2 after two periods, Vancouver evened things up at 4:01 of the third when Bartkowski blasted his fifth of the season past Anderson. The goal stood after an Ottawa coach's challenge for offside.
The Canucks continued to push, and Virtanen gave his team the lead at 10:59 on the power play when the rookie swatted a loose puck past Anderson for his fifth.
Mika Zibanejad rang a shot off the crossbar with under four minutes to go for the Senators with Miller down and out, but that would be as close as the visitors would come to getting an equalizer before Etem scored his second of the night into an empty net with under 30 seconds to go.
Tied 1-1 after the first, the teams traded chances in the second before Ottawa grabbed a 2-1 lead at 6:58 when Stone buried his 20th of the season on a short-handed 2-on-1 rush.
The Canucks got that one back just 1:23 later when Bartkowski's shot through traffic appeared to go off a Senators' stick and found its way through traffic.
Ottawa restored the lead with 2:35 left in the period when Marc Methot stepped around Etem with the teams playing 4-on-4 and fed Ryan, who ripped his 21st past Miller to make it 3-2.
Vancouver opened the scoring 4:38 into the first when Etem scooped a rebound past Anderson for his second.
Ottawa replied at 9:25 when Hoffman tipped home his 25th on a Phaneuf point shot seconds after a Senators' power play expired. The goal stood following video review to determine if the puck was touched by a high stick.
Stone had an opportunity to give Ottawa the lead on a short-handed breakaway in the period's final minute, but Miller stopped the initial shot, and the follow-up attempt was waved off because the whistle had gone.
Notes: The Senators beat the Canucks 3-2 in the nation's capital on Nov. 12. ... Vancouver forward Markus Granlund suited up for the first time with his new team following Tuesday's trade with Calgary that sent former first-round pick Hunter Shinkaruk the other way. ... Ottawa visits the Calgary Flames on Saturday, while Vancouver hosts the San Jose Sharks on Sunday.