Chris Neil and Kyle Turris had a goal and an 2, at Scotiabank Place.
Milan Michalek, Jason Spezza and Jim O'Brien scored and Erik Karlsson and Nick Foligno added two assists for the Senators, who have won five of their last six games. Robin Lehner made 28 saves in the win.
P.A. Parenteau finished with a goal and an assist, John Tavares scored and Travis Hamonic added a pair of helpers for the Islanders, who have dropped three of their last four games. Evgeni Nabokov was tagged for four goals on 23 shots in defeat.