Kovalchuk scored his second goal of the game with 2:01 left in overtime Friday night, leading Atlanta past the New York Islanders 5-4 after the Thrashers squandered an early three-goal cushion.
Kovalchuk took a pass from Marian Hossa, sped across the blue line and beat Mike Dunham with a shot just inside the far post.
"A game like this can change in minutes," Kovalchuk said. "It wasn't our best game, but we found a way to win it."
Kovalchuk, who has 26 goals on the season, also scored during a first-period spurt that caused the Islanders to yank starting goalie Rick DiPietro before the game was six minutes old.
But New York kept coming back, rallying to tie the score at 3 in the second period and bouncing back again to force overtime after Hossa put Atlanta back in front with a goal 19 seconds into the third.
In fact, the Islanders were pressing hard for the winning goal in the final minute of regulation. But Kari Lehtonen turned away several good chances, and the Thrashers won it in overtime.
"We've got to start better," said New York's Chris Campoli, who tied the score at 4. "You can't let a team like that get up 3-0. We battled all game, showed a lot of character and proved we're a good hockey team. ... But tonight, it was just too much, I guess."
The Thrashers got a scare when Hossa hobbled off the ice with an injured left knee early in the second period. The All-Star winger, who came into the night tied for the NHL lead in goals, was tripped by Islanders defenseman Freddy Meyer and slid into the boards behind the New York goal.
"I went straight-legged into the boards and my shin went sore and stiff," Hossa said. "I was afraid it was an old injury."
After hobbling to the locker room and missing the rest of the period, Hossa was back on the ice for the start of the third. The crowd began chanting his name when they noticed him lining up for the opening shift, and it didn't take long for him to draw an even bigger cheer.
Hossa got the puck at the side of the Islanders' net and flipped a shot over Dunham's left shoulder.
"It was a nice way to get back and give the team a little jump," Hossa said.
Campoli scored with 13:57 remaining in regulation, camping out in front of the crease and deflecting Meyer's slapshot into the net. Lehtonen complained about possible interference, but the officials ruled it was a legal goal after looking at the replay.
The Thrashers scored three goals on their first five shots.
DiPietro let in a long shot by Shane Hnidy, and Kovalchuk made it 2-0 after Glen Metropolit checked Radek Martinek off the puck in the corner. Steve Rucchin picked it up and zipped a pass in front of the net to Kovalchuk, who found himself with a big opening when DiPietro got caught sliding to his right, trying to anticipate the shot.
Jon Sim gave the Thrashers a seemingly comfortable lead, scoring off a two-on-one with Scott Mellanby to finish off DiPietro. Dunham took over in the goal for New York.
"You make that decision more to shock the team than anything else," coach Ted Nolan said.
Whatever the motivation, it worked. The Islanders peppered Lehtonen with 17 shots in the opening period, and Trent Hunter began chipping away at the big deficit with his 10th goal.
New York scored twice in the second to make it 3-3. With Meyer in the box for tripping Hossa, the Islanders got a shorthanded goal by Miroslav Satan, who knocked down a long pass by Martinek just outside the Atlanta blue line and swept in to beat Lehtonen.
Shawn Bates scored the tying goal after Alexei Yashin broke for the net, getting between Atlanta's two defenseman to create a perfect screen. Lehtonen didn't see the puck until it was past him.
"You've playing a first-place team and you're down 3-0 in their rink," Nolan said. "You have to give them credit for bouncing back."
NHL commissioner Gary Bettman will be in Atlanta on Sunday to unveil to logo for next year's All-Star Game at Philips Arena. ... New York defenseman Sean Hill was called for interference and hooking during the same sequence in the third period, sending him to the penalty box for four minutes.
Copyright by STATS LLC and The Associated Press
Arena: Philips Arena Location: Atlanta, Georgia
Referees: Don Koharski, Dan O'Rourke Linesmen: Thor Nelson, Anthony Sericolo
Attendance: 18,089 (97.5% full)
Team Stat Comparison
Power Play Goals
Power Play Opportunities
Shots on Goal
Shane Hnidy (5)
Assists: Niko Kapanen, Jon Sim
Ilya Kovalchuk (24)
Assist: Steve Rucchin
Jon Sim (12)
Assists: Scott Mellanby, Steve McCarthy
Trent Hunter (10)
Assists: Mike Sillinger, Andy Hilbert
Miroslav Satan (14)
(Shorthanded) Assists: Radek Martinek, Viktor Kozlov
Jason Blake (25)
Assists: Alexei Yashin, Chris Simon
Marian Hossa (31)
Assists: Slava Kozlov, Niko Kapanen
Chris Campoli (1)
Assists: Freddy Meyer, Jason Blake
Ilya Kovalchuk (25)
Assists: Marian Hossa, Garnet Exelby