Justin Williams scored his fifth goal in a five-game span for the Hurricanes, who outshot New York 35-25 and matched a season high with their third straight victory.
Erik Cole, Eric Belanger and Scott Walker also scored, while Cory Stillman had three assists and Ray Whitney added two.
Carolina's 26th-ranked power-play unit went four-of-nine against the Islanders' 24th-ranked penalty-kill. It was the Hurricanes' most productive performance on the power play since they scored five goals with the man advantage against Detroit on Nov. 29, 2002.
Chris Simon scored for the Islanders, whose two-game winning streak was snapped.