The 65 minutes of regulation and overtime between the Islanders and Flyers ended goalless, sending their Madison Square Garden clash to a shoot-out.
And the Islanders made it five wins from as many matches taken to the format this season, beating the Flyers before the latter could even have their customary three penalty shots.
Franz Nielsen and John Tavares scored the Islanders' goals in the shoot-out, to end the contest after just five shots across the two teams.
It was the Islanders' ninth win in their past 10 matches, but they still could not climb to the helm of the Eastern Conference's Metropolitan division - with the Pittsburgh Penguins holding form.
The Islanders and Penguins both have 30 points - Pittsburgh have a game in hand - after the latter edged the Boston Bruins 3-2 in overtime.
Evgeni Malkin scored 32 seconds into the additional period, to add to his game-equalising goal in regulation to earn the Penguins victory - in what was goaltender Marc-Andre Fleury's 300th win.
The Detroit Red Wings scored four goals in little over 21 minutes to down the Ottawa Senators 4-3.
Detroit moved third in the East's Atlantic standings, level on points with fourth-place Boston - but ahead given they have two games in hand.
Jason Zucker scored twice and Mikko Koivu had two assists as the Minnesota Wild won 4-1 over the Florida Panthers.