"The guys were doing great setting me up tonight," said Kovalchuk. "They're the ones who deserve all of the credit, but it sure is nice to be scoring goals again and winning games."
New Jersey sits in sixth place in the Eastern Conference, two points back of Philadelphia.
Andrew MacDonald scored the lone goal for the Islanders, who had won their previous two. Evgeni Nabokov was tagged for all five goals on 20 shots in the loss.
"We moved the puck and kept it simple, but the wheels fell off in the third," said MacDonald. "It's tough to see something like that this time of the year."
Kovalchuk got the scoring started 8:07 in when he backhanded home the rebound off his own one-timer from the low, left side.
It was 2-0 3:33 into the second off a power-play goal as a nice passing play saw Elias send it from the right corner to the high slot, where Marek Zidlicky fired it over to the left circle and Kovalchuk one-timed it in.
MacDonald got his squad on the board with 3:39 to play in the middle stanza as his shot of a bouncing puck from behind the goal line at the left side hit off the arm of Brodeur and went in.
The Devils, though, got the goal back 7:05 into the third when Elias knocked in his second chance from in front of the net for his 23rd of the year.
Kovalchuk completed his 13th career hat trick and scored for the 29th time on the season just 64 seconds later as his one-timer from the slot went in on the far side.
David Clarkson capped the rout with a redirection in front with 4:01 to play.
These two will face each other again on Saturday in New Jersey. It will be the third straight game that the Islanders play the Devils, while New Jersey had a game against the Rangers on Tuesday after playing the Islanders on Sunday...Each team has won twice in the season series...The Devils went 1- for-3 on the power play, while the Islanders were 0-for-3.