Alexei Yashin and Sean Hill also scored goals for New York, which is 5-1-1 in its last seven games. Evgeni Malkin spoiled DiPietro's shutout bid in the third period with his 11th goal for the Penguins, and Jocelyn Thibault turned aside 26 shots. Pittsburgh, which lost for the second time in seven games (4-2-1), was without second-year star Sidney Crosby for the second straight game.
The 19-year-old centre took part in the pre-game warmup, but was forced out of the lineup by a sore groin.
Malkin, the Penguins' latest star rookie, appeared to be injured late in the game following a shoulder-to-shoulder hit by Islanders defenceman Brendan Witt. Witt's check at the Islanders blue line knocked Malkin's helmet off, and the centre skated directly off the ice toward the dressing room.
DiPietro kept the Penguins off the board until late and was helped when the Islanders killed a 51-second, two-man disadvantage halfway through the opening period. Shortly after a faceoff, Richard Park - the only forward on the ice for New York - broke his stick. Park then blocked two shots while the Islanders were short-handed.
Yashin opened the scoring at 2:12 of the second period. Thibault tried to clear the puck behind the net, but it hit Miroslav Satan. Satan found Yashin, parked by the left post, and the Islanders captain put the puck in the open left side.
The goal extended Yashin's point streak to four games (3-3-6). He has 15 points in 12 games (seven goals, eight assists), and leads the team with 26 points (10 goals, 16 assists).
Satan earned his 300th NHL assist on the play and is one goal away from reaching 300.
While trailing 1-0, Pittsburgh had the potential tying goal disallowed at 6:57 of the second period when it was ruled that Malkin, at the bottom of a pileup in front of the Islanders net, threw the puck past DiPietro.
Colby Armstrong was denied a goal by DiPietro's best save of the period. DiPietro snared a rising 30-foot slap shot from the top of the right circle with his glove at 14:22.
Satan made it 2-0 with his fifth goal at 5:24 of the third. As the teams skated 4-on-4, Satan tipped Brendan Witt's right point shot past Thibault.
Hill scored his first of the season at 8:31 with a rising slap shot from the left point.
Malkin broke DiPietro's shutout bid at 12:46 with a wrist shot from the left circle.
Notes:: The Islanders didn't sell out any of their first 11 home games, but drew their biggest announced crowd of the season, 15,625. Pittsburgh was 0-for-9 on the power play.