Kamil Kreps and Stephen Weiss also scored for the Panthers, who moved within five points of eighth-place Philadelphia in the Eastern Conference playoff race. Brett McLean added an empty-net goal.
Florida has 74 points and is tied for 10th in the conference with Southeast Division-rival Washington.
Bill Guerin and Blake Comeau scored for the Islanders, who have lost six of seven and dropped to 13th in the Eastern Conference.
This was Florida's second victory over the Islanders in 10 days. The Panthers recorded a 1-0 road win on March 2 when backup Craig Anderson stopped 53 shots.
Tomas Vokoun was in net for Florida this time and made 27 saves.
Rick DiPietro stopped 28 shots for the Islanders.
Skrastins, acquired from Colorado last month at the trade deadline, scored his second goal of the season and first for the Panthers.
He stopped the Islanders' clearing attempt at the blue line and then fired a slap shot that beat DiPietro to the far side after the goalie was screened by defenseman Matthew Spiller.
Weiss broke a 1-1 tie at 1:05 of the third period when his rebound shot from a sharp angle went off DiPietro's pad and landed behind him.
Comeau tied it at 7:18 with a power-play goal. He scored to the glove side with a wrist shot from the slot.
After a scoreless first period, the teams traded goals in the first 1:23 of the second.
Guerin gave the Islanders the lead 28 seconds in when he tapped home a pass from Richard Park on a 2-on-1. Kreps tied it 55 seconds later after taking a feed from Ville Peltonen on another 2-on-1.
