Five players scored, and Ilya Sorokin made 19 saves for the Islanders (17-6-4), who extended their point streak to 10 games (9-0-1) and are the only team in the NHL without a regulation loss at home (12-0-2). Ryan Pulock had two assists.
"I think we did a lot of good things off the start," Pulock said. "The first couple of periods, we played north. Obviously it got away from us a little bit in the third, where we weren't as sharp, but there's things that we can clean up every game, no matter the outcome."
New York lost forward Anders Lee to an apparent lower-body injury at 12:56 of the first period following a collision with New Jersey forward Pavel Zacha. The Islanders captain leads New York with 12 goals and was playing his 295th consecutive game.
"I don't have an update," Islanders coach Barry Trotz said. "Obviously, he got twisted up there. He's being evaluated and we'll see where he is in the morning.
"Anders is our captain, he's our leader. He does everything right. He's such a good pro and such a good person. He's got the total respect of our whole team and the bench all the time. [There are] very few times Anders Lee struggles to get up from any kind of hit or anything. He's a tough, tough man and everybody on our bench felt for him there."
Mackenzie Blackwood made 29 saves for the Devils (8-12-3), who have lost seven of eight.
It was the first of a three-game set. The teams play back to back at New Jersey on Saturday and Sunday.
"They were dominating us in the first two periods; shots reflected that (25-12), score reflected that (4-0)," Devils forward Kyle Palmieri said. "I mean, we have these guys two more times over the weekend, and that's something that we need to correct going into the weekend."