Bryan Rust scored in a third straight game, Jeff Carter scored for the second time in three games, and Casey DeSmith made 34 saves for the Penguins (31-14-3), who completed a three-game sweep of the Devils.
Pittsburgh, which is 7-1-1 in its past nine games, is second in the MassMutual East Division, one point behind the Washington Capitals and two ahead of the New York Islanders. Washington defeated New York 6-3 later Saturday.
Jack Hughes and Miles Wood scored for New Jersey (14-27-6), which has lost nine straight in regulation.
Mackenzie Blackwood returned after missing two games with an upper-body injury and made 33 saves.
"We're trying to play our best all the time," Blackwood said. "It's a learning experience for our team right now. Trying to find ways to win. Trying to find ways to play the right way."
The Devils have not had a lead in eight consecutive games since taking a 1-0 lead at 3:01 of the first period in a 6-4 loss to the Penguins on April 9.
"I really think it's an opportunity for all our young players to make an impression," New Jersey coach Lindy Ruff said. "I think every player wants that opportunity. They say, 'Well, I don't get enough ice time. I don't get enough time to play.' ... So it's an opportunity for those players to make a statement that they can be a difference-maker for us."