"We just seem to play well against them," said DiPietro, who has given up five goals in four games against New Jersey this season. "You find if you play long enough, there are certain teams you play well against. The last couple of years, it has been the Devils."
Mike Sillinger also scored for New York, which has won four of the five meetings in regulation. The Islanders have won six straight overall against the Devils.
Travis Zajac scored for New Jersey, which had a three-game winning streak snapped in losing for only the seventh time in 26 games (19-6-1).
"It doesn't take a rocket scientist, does it?" Devils forward Patrik Elias said of the Islanders' streak. "They are playing well against us. They are playing well against Philly and us. Those are big points to lose. We had our opportunities to get back in the game, but it's still disappointing to lose. Their goaltender played awesome tonight."
DiPietro was spectacular in the third period, stopping 15 of 16 shots, including one in close by Dainius Zubrus in the final 90 seconds that had the Devils center looking up at the rafters in the Prudential Center.
"There were a couple of pucks whacked away and I was able to get my glove up on it," DiPietro said of Zubrus' shot from less than 10 feet away.
Guerin downplayed the Islanders' dominance.
"Have we come out on top every game? Yes!" Guerin said. "It's not like it's been a dominating effort by us each and every single time. They have been good hockey games."
DiPietro, who shut out the Devils in his only other game at the Prudential Center, had to work hard in the final six minutes to preserve the win.
Brian Gionta, whose shot was deflected by Zajac on the Devils' goal, had a good chance from the right circle with six minutes to play. Jamie Langenbrunner, who was stoned in close early in the game, was stopped in close again seconds later.
Zajac and Zubrus were also stopped in close in the final minutes.
"Tonight, Ricky saved us a couple of points," Guerin said. "I thought we played a solid game, but when they turned it up and got good scoring opportunities, Ricky was there. He saved at least four goals I can think over. He kept us in it. He's been doing it all year for us."
The Devils are now winless in nine games against their New York-area rivals, including an 0-2-2 record with the Rangers.
"Nine straight is something we have to take notice of obviously," Langenbrunner said.
"It's nine straight against the New York teams," Gionta added. "We have to find a way to win."
The Islanders had a two-man advantage when Guerin gave them the lead with less than five minutes to go in the first period. Colin White and Mike Mottau were both given 2-minute penalties at the same time.
Mike Comrie took a pass from Miroslav Satan low in the right circle and sent a cross-ice pass to Guerin low in the left circle. His quick shot went in and out of the net so fast that everyone kept playing other than Guerin.
Sillinger scored all alone in front in the second period after taking a great centering pass from behind the net by Trent Hunter.
Zajac scored at 7:11 of the final period, tipping a shot by Gionta. DiPietro got a piece of the puck, but it trickled between his pads and he seemed to knock it into the net trying to prevent it from going in.
