Ottawa took the best-of-seven series 4-1 and put a punctuation mark on its dominance in moving on for the first time since 2007, when the Senators lost in the Stanley Cup finals to the Anaheim Ducks.
The victory gives Ottawa time to rest up and heal bruises from the physical series before the conference semifinals begin next week.
Zack Smith, Kyle Turris, Daniel Alfredsson and Erik Condra also scored for Ottawa, underdogs as the seventh seed in the East, but bolstered down the stretch by the return of top players on defence Erik Karlsson and Jared Cowan.
P.K. Subban scored for injury-struck Montreal.
Penguins 4, Islanders 0.
PITTSBURGH (AP) — Tomas Vokoun stopped 31 shots in his first playoff start in six years and the Penguins took a 3-2 lead in their first-round series.
Sidney Crosby, Tyler Kennedy and Douglas Murray scored during a seven-minute stretch in the second period and Kris Letang added a power-play goal in the third as Pittsburgh moved a step closer to advancing to the second round.
Game 6 is Saturday in New York.
Evgeni Nabokov made 23 saves for the Islanders, but also gave up breakaway goals to Crosby and Kennedy and botched a lazy wrist shot from Murray that gave the Penguins all the offence they would need.
Vokoun was thrust into the lineup after Pittsburgh coach Dan Bylsma benched Marc-Andre Fleury, who had started 79 straight post-season games but struggled in a 6-4 loss in Game 4. The 36-year-old Vokoun didn't look intimidated by the stage as the Penguins restored a little order to a wide-open series.
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