Jack Eichel, Evan Rodrigues and Ryan O'Reilly also scored for the Sabres, who snapped a four-game losing streak. Goalie Robin Lehner made 26 saves.
John Tavares, Ross Johnston and Anders Lee scored for the Islanders, who trailed 3-0 before tying the game on Lee's goal 73 seconds before Reinhart's game-winner. The loss cost New York a chance to move past the idle Columbus Blue Jackets into sole possession of the second wild card in the Eastern Conference.
Goalie Jaroslav Halak recorded 18 saves.
The goals by Eichel and Rodrigues came on the Sabres' only two shots in the first 13-plus minutes of the first period. Eichel scored when he was left all alone in the middle of the left faceoff circle while Rodrigues scored after Marco Scandella fired a puck that bounced off the back wall and right to Rodrigues.
Buffalo extended its lead to 3-0 at the 7:18 mark of the second, when O'Reilly's slap shot from just in front of the blue line sailed over a leaping Reinhart and past Halak.
The Islanders began crawling back thanks to an impressive individual effort by Tavares with 6:54 left in the period. Tavares was leveled near the boards by Scandella but got back up and followed Brock Nelson's shot by poking the puck free from Lehner in the crease and putting it into the net.
Johnston pulled the Islanders within one 7:30 into the third after Cal Clutterbuck won a battle for the puck deep in the Sabres zone and dished to Johnston, who fired a shot under Lehner's arm.
Lee tied the game on a power-play goal with 5:27 left, when he pounced on the rebound of a Josh Bailey shot and snuck it into the corner of the net.
--Field Level Media
NY Islanders | Buffalo | |
Ross Johnston 1 | Points | Sam Reinhart 3 |
Ross Johnston 1 | Goals | Sam Reinhart 1 |
Josh Bailey 1 | Assists | Sam Reinhart 2 |
Anders Lee 1 | Power Play Goals | Ryan O'Reilly 1 |
N/A | Short Handed Goals | N/A |
Jaroslav Halak .818 | Save Percentage | Robin Lehner .897 |
Jaroslav Halak 18 | Saves | Robin Lehner 26 |
Team | Shots | Goals | Power Play | Penalty Kill | Penalty Mins | Face Offs Won |
NY Islanders | 29 | 3 | 1-3 | 1-2 | 4 | 16 |
Buffalo | 22 | 4 | 1-2 | 2-3 | 6 | 24 |