The Islanders had been mired in a 14-game road losing streak, as the team's last road victory took place on November 24, in Montreal. Trent Hunter, Doug Weight and Tim Jackman also scored for the Isles, who have won two in a row after an eight-game losing streak.
Yann Danis made 33 saves in the win for New York.
Rich Peverley had a goal and two assists for the Thrashers, who have lost three in a row. Zach Bogosian, Marty Reasoner and Ilya Kovalchuk also tallied, and Kari Lehotonen allowed four goals on 15 shots in the first period before being pulled. Johan Hedberg stopped 17-of-18 shots in relief but took the loss, as Atlanta couldn't complete the comeback.
Hunter got the Islanders on the board just 55 seconds into the game, beating an out-of-position Lehtonen from the right circle for his 12th tally of the year.
Okposo gave the Isles a 2-0 lead after a nice pass across the crease from Blake Comeau left a wide-open net at 7:29 of the opening frame. A few minutes later, Lehtonen misplayed a rebound and the puck just sat in the crease until Jackman easily put it to make it 3-0.
New York took a 4-0 lead with 6:43 left in the first, as Weight outworked the Atlanta defense for a loose rebound and beat Lehtonen, who was pulled as a result.
Hedburg, his replacement, stopped 15-of-15 shots in the remainder of the first and second periods combined, but Atlanta's offense was shut out as well, and the 4-0 score carried over to the third.
Bogosian put the Thrashers on the board 26 seconds into the third, and Peverley scored a power play goal at the 6:20 mark on a nice backhand move that beat Danis to make it 4-2.
Reasoner's wrap-around goal through Danis' legs made it 4-3 with 11:24 left, but Okposo's goal at the front of the crease put the Isles back up by two with 7:21 to go.
Kovalchuk tipped in a shot out in front to pull the Thrashers to within 5-4 with 58 seconds left, but the team fell short, as pulling Hedberg for the extra attacker proved to be fruitless.