P.K. Subban scored for New Jersey (15-19-6), which won its third game in a row despite playing without rookie center Jack Hughes because of an upper-body injury. The Devils are 4-0-1 in their past five and 6-2-1 in their past nine.
"You can tell the guys are out there making plays, skating, being tenacious on the forecheck, defending the right way," said New Jersey's Mackenzie Blackwood, who made 10 of his 29 saves in the third period. "But you can also see they're not scared to make plays. They bought in and they're blocking shots that are huge and committing in the D zone. It's just a great, all-around team game out there."
WATCH: [All Devils vs. Islanders highlights]
Brock Nelson scored for New York (25-11-3), which has lost its past four home games (0-3-1), all at Nassau Coliseum. Semyon Varlamov made 29 saves.
"We've lost four games here in this building, and really [against] nonplayoff teams," coach Barry Trotz said. "There's not any bad teams in the National Hockey League; this team's playing very well right now, they're playing free. They got the elephant out of the room with the [Taylor] Hall trade (to the Arizona Coyotes). They're getting really good goaltending; I thought Blackwood was excellent for them, I thought Varlamov was excellent for us.
"We haven't found the back of the net. We've got to score more than a goal. If we have to win that way, we'll have to do it, but we had some chances early, we didn't bury it, and they hung around and around. I think we didn't really take it to the next level unfortunately, but it's on us."
Hischier scored the game-winner unassisted at 1:09 of the third. He won a face-off in the right circle of the Islanders zone against Nelson, powered his way around the New York center, and stuffed a shot past Varlamov to give New Jersey a 2-1 lead.