Tyler Kennedy scored twice in regulation, and Jordan Staal added a goal. Sabourin turned aside 19 shots to boost the Penguins to their third straight win. Pittsburgh had star forward Sidney Crosby in the lineup one day after he left practice early Friday due to an undisclosed injury.
Doug Weight, Tim Jackman and Andy Hilbert scored for New York, and MacDonald stopped 29 shots.
Pittsburgh outshot the Islanders 18-1 in the final period, and tied the game on their 17th shot with 3:15 left. New York squandered a multigoal lead in the third period for the fourth time in five games.
The Islanders did two things well in the opening period. They held Pittsburgh to just two shots and grabbed a 1-0 lead. Weight scored his third goal of the season at 16:27 when he wristed a shot from just inside the left point over Sabourin's rising glove hand.
The Penguins tied it 2:16 into the second when Kennedy completed a give-and-go with Mike Zigomanis by backhanding the puck into a nearly open net.
Jackman, recalled earlier in the day by the Islanders from Bridgeport of the AHL, took the rebound of Weight's shot and buried it for his first of the season and third in the NHL. That gave New York a 2-1 lead at 8:51.
Hilbert made it 3-1 at 14:30 off a nice centering feed from Kyle Okposo. Staal narrowed the gap to one at 16:01 on a breakaway, putting a backhander past MacDonald.
Kennedy tipped in a point slap shot from Alex Goligoski to tie it 3-3.
