The Islanders surely needed a home-ice lift after a rough three-game trip that dropped them into a wild-card position.
On a night when the captain John Tavares played his 500th N.H.L. game, and with a chance to put some real distance between themselves and the only team with a bona fide chance of knocking them out of a playoff spot, the Islanders fell flat with a dispiriting 4-1 loss to the surging Philadelphia Flyers.
It was the first regulation defeat at home for the Islanders since Jan. 25 against Detroit and narrowed their division lead over the Flyers to 3 points.