Elias missed the first 13 games of the season with a groin injury. He has played in 10 games since then, picking up three goals and seven assists. He has also helped revive Rolston, who has four goals in his last four games after scoring only four in the first 19.
"It's chemistry," Rolston said. "It makes a huge difference. Patrik is a guy looking for other players all the time. I've never been a guy who can make a ton of plays like Patrik can, I'm more of a guy that can find areas and get the puck on the net. Patrik finds me -- it's huge."
Elias sees the difference in Rolston.
"He's been playing better the last four or five games," Elias said. "We can be even better. We're talking to each other about what we want to do out there. He's a shooter, so I try to give him opportunities to get the shots off."
Mike Mottau and Zach Parise had the other New Jersey goals with Parise extending his career-high point scoring streak to 10 games. Brodeur was back in net one day after setting a record for minutes played by a goaltender.
The Devils extended their home-ice winning streak to six.
Richard Park scored the Islanders' goal, beating Brodeur with a shot from above the right circle at 11:18.
Although both teams played Friday afternoon, the Islanders got off to a better start. New York hemmed New Jersey in its zone for most of the opening minutes with Brodeur making a sharp pad save on Trent Hunter's drive.
After Park staked the Islanders to the lead, Brodeur held the deficit at a goal by denying a close in bid from John Tavares.
The second period was all New Jersey.
The Devils pulled even 54 seconds into the period with a fancy goal from Mottau. Pinching along the right boards, he skated deep into the zone and carried behind the New York net before dumping a backhander into the crease that bounced off the skate of an Islander defender. The puck eluded Martin Biron for Mottau's sixth goal in 202 career games.
The Devils took the lead when Rolston, set up nicely by Elias, beat Biron from the slot for a power-play score at 12:06.
New Jersey's Andy Greene came within inches of tacking on two more goals in the period, ringing one shot off the crossbar and another off the post.
The Devils put the game away with four goals in the third. After a rousing third-period comeback to beat the Stanley Cup champion Penguins on Friday, the Islanders collapsed against the Devils.
"The third period is the game, most of the time," Biron said. "That was the difference today. It's our own wrong doing. When we don't do the right things, it's going to happen. We got lucky earlier in the game, they hit a few posts. If you keep playing with fire, you're going to get burned."
Elias cashed in a five-on-three power play to put the Devils up 3-1. Parise and Rolston soon followed with goals 38 seconds apart, while Elias closed out the scoring with 45 seconds left.
Devils RW David Clarkson suffered a fracture above the right ankle when struck by Zdeno Chara's slapshot Friday in New Jersey's 2-1 shootout win in Boston. New Jersey president and GM Lou Lamoriello said Clarkson will out 4-to-6 weeks ... Clarkson joins the Devils lengthy list of injured players that includes C Dainius Zubrus (fractured knee cap), C Rob Niedermayer (upper body injury), D Paul Martin (fractured forearm), D Johnny Oduya (lower body) and LW Jay Pandolfo (dislocated shoulder). The Devils called up forwards Ilkka Pikkarainen and Vladimir Zharkov from Lowell (AHL) while returning D Tyler Eckford to that club ... The Islanders scratches were C Rob Schremp, D Andy Sutton and RW Blake Comeau ... Brodeur could become a U.S. citizen Tuesday, if he passes the citizenship examination that morning.