Mikhail Grabovski, Anders Lee and Colin McDonald had given the Islanders a three-goal lead on Sunday at the First Niagara Center, with Travis Hamonic registering a pair of assists.
Marcus Foligno and Drew Stafford brought Buffalo back into the game but it wasn???t enough.
Montreal Canadiens defeated the Boston Bruins 3-1 thanks to 34 saves from goaltender Carey Price.
Dale Weise and Max Pacioretty notched a goal and an assist each to help the Canadiens to their first regular season clean sweep over the Bruins since 2007-08.
Tampa Bay Lightning beat the Anaheim Ducks 5-3 despite Ryan Getzlaf scoring his 200th NHL goal.
Brian Boyle scored twice and Valtteri Filppula, Nikita Kucherov and Ryan Callahan were also on the scoreboard for the Lightning.
Ales Hemsky scored 1:02 into overtime to gift Dallas Stars a 3-2 win over the New York Rangers.
Chris Kreider has equalised in the closing moments for the Rangers but Hemsky would have the last say in the power play at 18:04 of the third.
Mark Streit, Wayne Simmonds and Jakub Voracek netted as the Philadelphia Flyers beat the Washington Capitals 3-1.
Filip Forsberg scored a power play equaliser and the shootout winner as the Nashville Predators edged the Florida Panthers 3-2. Chicago Blackhawks beat the St. Louis Blues 4-2, and Winnipeg Jets were 5-3 winners over Colorado Avalanche.