Kessel had two goals and two assists, ending his seven-game goal drought. Crosby had a goal and two assists, and has 18 points (nine goals, nine assists) in his past 11 games.
"I thought we did a good job in not beating ourselves, for the most part," said Crosby, the Penguins captain. "Found a way to keep our speed through the neutral zone and be on the forecheck. When we do that, we get our chances eventually. So I think we played a smart game. That's what it really came down to."
WATCH: [All Islanders vs. Penguins highlights]
Kris Letang scored twice, Riley Sheahan scored, and Casey DeSmith made 19 saves for Pittsburgh (12-10-5), which has won two straight games after losing its previous two.
Brock Nelson and Anders Lee scored for New York (13-11-3), which is 1-3-1 in its past five games. Thomas Greiss made 16 saves on 21 shots, and Christopher Gibson made six saves on seven shots after replacing Greiss to start the third period.
"It was too friendly of a game," Islanders coach Barry Trotz said. "There wasn't enough skin invested in the game, right across the board. We need a couple saves. Some [defensemen] could play a little bit better. Some of our forwards who are a little more physical could be more assertive in that area, and our skill guys are going to have to produce. No one was immune today."
Letang has seven goals in 26 games this season after scoring nine in 79 games last season and five in 41 games in 2016-17. He gave Pittsburgh a 1-0 lead at 8:34 of the first period by one-timing a slap shot.