Kozlov's third goal gave Atlanta its first lead with 8:09 left in regulation as the Thrashers beat Ottawa 5-4 on Wednesday night to hand the Senators their first five-game losing streak in 10 years.
Once again, the Senators couldn't hold a lead. Goalie Martin Gerber continued to struggle as he fell to 2-6-1 while stopping only 26 of 31 shots.
The Senators blew 3-1 and 4-2 advantages. It was the third straight game that Ottawa blew a lead.
"I felt pretty confident, but I couldn't finish it," Gerber said. "They have a very high-skilled team.'
The Senators, who last lost five straight games from Feb. 22-March 9, 1996, led 2-0 in a 3-2 loss to Carolina on Saturday night and couldn't hold a 3-0 lead in a 4-3 loss to Washington in overtime on Monday night.
"We have to find some way to break this cycle," said Ottawa's Joe Corvo. "We have to keep working. I know that sounds stupid."
The Thrashers pulled even at 4-4 on Ilya Kovalchuk's wrist shot past Gerber about four minutes into the third period. Kozlov's third goal of the game about 12 minutes into the period gave Atlanta its first lead.
Kozlov gave credit to Thrashers goalie Kari Lehtonen, who stopped 19 shots in a relief role, shutting out the Senators for the last period and a half.
"Kari came in and he gave us a chance," Kozlov said. "He made some really good saves to keep us in it when we were down two goals."
Ottawa coach Bryan Murray planned to give Gerber a rest against Atlanta, but backup goalie Ray Emery suffered a sprained wrist in practice Wednesday.
Murray, already under pressure in Ottawa, said his team gave a good effort.
"That's as hard-working game as we've had this year," Murray said. "We had lots of scoring chances. I never talk to the guys after we lose a game in the two years I've been here, and tonight I did. I thought they played extremely hard, very focused and didn't give up many scoring chances at all."
The Thrashers, who lead the Southeast Division, won their fourth straight game despite changing goalies midway through the game.
Johan Hedberg, who had allowed only 2.01 goals per game in three straight wins, was pulled after Ottawa took a 4-2 lead midway through the second period. Hedberg stopped 15 of 19 shots before giving way to Lehtonen.
"I got out there and got lucky in the first two minutes," Lehtonen said. "After that, I found my game and hockey was fun again. ... It's great to have two good goalies on the team."
The Thrashers were called for four first-period penalties, providing the Senators repeated opportunities to shake out of their power-play slump.
Ottawa was 0-for-16 on the power play in its last three games. The Senators failed on two power-play opportunities against Atlanta before Daniel Alfredsson broke the slump with a goal for a 2-1 lead.
Chris Kelly's tip-in about six minutes into the second period pushed the Senators' lead to 3-1.
Ottawa's first penalty, a holding call on Anton Volchenkov, came 7:36 into the period, and less than a minute later a delay call against Andrej Meszaros gave Atlanta a two-man advantage.
Only 14 seconds later, Kozlov, positioned in front of the net, tipped in a pass from Marian Hossa to cut Ottawa's lead to 3-2.
Antoine Vermette's short-handed goal at the end of Atlanta's power play gave Ottawa a 4-2 lead, prompting Thrashers coach Bob Hartley to change goalies.
"We got a great run from Johan, but after the fourth goal I felt Johan was not as sharp as he had been," Hartley said. "The first 40 minutes were not the kind of hockey that we can play, and I felt that by changing the goalies we could try to flip the game around."
Kozlov's second goal of the second period cut Ottawa's lead to 4-3.
The Senators opened the scoring in the first period with Jason Spezza's sixth goal. Atlanta answered with a short-handed breakaway goal by Brad Larsen for a 1-1 tie.
- Emery was in uniform one day after suffering a sprained wrist in practice.
- Kozlov's last hat track came against Ottawa on Jan. 2, 2006.
- Hossa had three assists.
- The Thrashers have hat tricks in back-to-back games for the first time in team history. Kovalchuk had three goals in Monday's 5-3 win over Boston.