"It's nice when your third and fourth lines can contribute offensively," Hossa said. "These guys may not score many goals, but the ones they do score are usually big goals."
Jason Blake scored the only goal for New York, which had a three-game winning streak snapped. Rick DiPietro made 15 saves on a night he struggled in the nets.
The Thrashers finished a stretch in which they played seven of eight on the road. They went 4-1-2 in that stretch and are tied with Buffalo for the Eastern Conference lead. Both teams have 23 points.
Atlanta took a 1-0 lead just 2:59 in when Vigier found a loose puck during a scramble in front and flipped a backhanded shot over DiPietro.
Vigier broke his nose during Friday night's game at Washington, which prompted Atlanta coach Bob Hartley's to gesture toward the officials. He was fined $10,000 by the NHL on Saturday.
"As a coach, I have to protect my players," Hartley said. "I understand the league has rules and are there to support their referees. I was wrong, and I'll move on.
"The Washington doctors did a great job. Vig - his nose was way off - and he told me on the plane ride he wanted to play, and didn't even want to wear a shield. You talk about the toughness of hockey players, and there's a big example."
The Thrashers scored twice in a 69-second span late in the period to go ahead 3-0.
Hossa was the beneficiary of a poor clearing attempt by DiPietro. The puck was picked off the left wall by Niko Kapanen, who quickly fired a shot that was tipped in by Hossa at 17:18. His 12th goal moved him into a tie with New York Rangers forward Brendan Shanahan for the NHL lead.
"Niko threw me a half-pass, half-shot, and I was just trying to tip it," Hossa said.
Larsen made it 3-0 at 18:27 by redirecting a shot that DiPietro appeared ready to catch.
"We had a strong forecheck," Hartley said. "We felt the best way to neutralize their great scoring forwards was to stay on the puck, and it paid off with three big goals in the first period."
Islanders coach Ted Nolan didn't consider replacing DiPietro after the period, even if the fans were chanting for backup goalie Mike Dunham.
"This wasn't one of his better games," Nolan said of DiPietro, who signed a 15-year contract with the Islanders before this season. "He had a shaky period, but everyone has a bad period. I didn't think of pulling him. He has to learn to fight his way through these things."
Blake got the Islanders on the board with his team-leading eighth goal at 5:13 of the second period. His right circle wrist shot hit the crossbar and bounced off Hedberg's back and into the net.
Alexei Yashin's secondary assist on Blake's goal gave the Islanders captain a team-leading 12 assists and 17 points. Yashin has points in four straight games (2 goals, 4 assists), and six of seven (3 goals, 10 assists).
McCarthy scored with 1:02 left in the period on a power play rebound to make it 4-1.
Thrashers forward Scott Mellanby was injured at 7:41 of the third period after he was checked into the boards by Yashin. Mellanby appeared to hurt his left shoulder or arm. After the game, he said he was fine.
"I got a stinger," Mellanby said. "I kind of twisted my neck. My shoulder is fine, but I'll be sore tomorrow."
New York lost defenseman Tom Poti at 10:27 when he was inadvertently elbowed in the face.
Islanders forward Mike Sillinger lamented a missed opportunity to take advantage of Atlanta's second game in two nights.
"They were playing back-to-back," Sillinger said. "We were the fresh team, but we weren't ready. We have to be ready to play. We can't let that happen in our building."
After 16 games last season, Atlanta was 6-9-1. ... The Thrashers are second in the league in goals scored with 57, trailing Buffalo by two. ... Islanders television color commentator Billy Jaffe worked for the Thrashers on radio and TV the previous six seasons.
Copyright by STATS LLC and The Associated Press
Arena: Nassau Veterans Memorial Coliseum Location: Uniondale, New York
Referees: Marc Joannette, Dan O'Halloran Linesmen: Andy McElman, Steve Miller
Attendance: 12,394 (76.1% full)
Team Stat Comparison
Power Play Goals
Power Play Opportunities
Shots on Goal
J.P. Vigier (2)
Assists: Jim Slater, Glen Metropolit
Marian Hossa (12)
Assist: Niko Kapanen
Brad Larsen (2)
Assists: Bobby Holik, Scott Mellanby
Jason Blake (8)
Assists: Alexei Zhitnik, Alexei Yashin
Steve McCarthy (1)
(Power Play) Assists: Marian Hossa, Ilya Kovalchuk