Mathew Barzal and Scott Mayfield each had a goal and an assist, and Semyon Varlamov made 20 saves for the Islanders (14-6-4), who have a seven-game point streak (6-0-1) and are the only team in the NHL without a regulation loss at home (9-0-2).
"It's just nice being at home; I think any team can attest to that," Barzal said. "You're comfortable, you've got your own stall, your own locker, you're at home eating well. I think we've been all right on the road as well (5-6-2), but just something about being at the Coliseum and just maybe probably having a little bit of extra juice. It's a tough thing to explain, but it's just really comfortable being at home."
Jacob Bryson and Sam Reinhart scored, and Carter Hutton made 24 saves for the Sabres (6-13-3), who have lost six in a row.
The loss came one day after general manager Kevyn Adams called out Buffalo's competitiveness and said everything is being evaluated, including coach Ralph Krueger.
"It's just mental toughness at the moment," Krueger said. "I mean, the National Hockey League this year is not a league of people running each other over, and without the fans in the building, the physicality is definitely in a different place than it would usually be. We're losing battles in 1-on-1 situations that are hockey situations.
"It's not the toughness of old, it's the toughness of new, which is you've got to be inside, you've got to grind it out, you've got to be persistent and you've got to win your individual battles."