"When you give a team a two-goal lead in the first period, it's tough to dig yourself out of it," Senators center Chris Kelly. "They kept rolling. We're in a slump, a tough spot right now."
The Thrashers scored the go-ahead goal on defenseman Pavel Kubina's slap shot 17:08 into the first, following Peter Regin's tying goal at the 7:29 mark of the first period.
Kovalchuk made it 3-1 with a wrister at 18:31 that gave him 17 points in his last 20 games.
Eric Boulton, whose tip-in made it 1-0 on the power play 3:36 into the first, credits Anderson with canceling the players' off day Sunday and scheduling a rigorous workout.
For the first time since Nov. 30, when the Thrashers beat Florida 4-3 for their most recent regulation victory, Boulton thought the team played intensely for 60 minutes.
"We were pressing," Boulton said. "We got a couple of quick goals early but we kept pressing and got the win."
Todd White scored his first goal in 35 games to give the Thrashers a 4-1 lead early in the second.
Tobias Enstrom put the Thrashers up 5-1 with a wrister from the left circle 9:43 into the second. Kovalchuk, after controlling his own rebound, passed from behind the net for Enstrom's fourth goal.
"We had two or three scoring chances from point blank on breakaways," Ottawa coach Cory Clouston said. "Obviously, we've got to score those opportunities, and when they get their chances, we've got to make the save."
Bryan Little made it 6-1 early in the third, scoring on a breakaway for his sixth goal.
Thrashers defenseman Chris Thorburn thinks his team set the tone in practice.
"We worked hard in practice on battling hard and trying to get some crease goals," Thorburn said. "It paid off for us tonight."
Atlanta defenseman Christoph Schubert's night ended midway through the first with a game misconduct and a major boarding penalty against Ottawa F Jonathan Cheechoo. ... The Thrashers last scored three first-period goals on Dec. 19, but lost 5-4 despite chasing New Jersey goalie Martin Brodeur before the second. ... White has just four goals through 44 games. He played a full 82-game schedule last year and finished with 22.
Copyright by STATS LLC and The Associated Press
Arena: Philips Arena Location: Atlanta, Georgia
Referees: Dean Morton, Tim Peel Linesmen: Jean Morin, Jay Sharrers
Attendance: 10,017 (54.0% full)
Team Stat Comparison
Power Play Goals
Power Play Opportunities
Shots on Goal
Eric Boulton (2)
(Power Play) Assists: Slava Kozlov, Todd White
Peter Regin (6)
Assists: Chris Neil, Jarkko Ruutu
Pavel Kubina (5)
Assists: Ron Hainsey, Ilya Kovalchuk
Ilya Kovalchuk (26)
Assists: Chris Thorburn, Rich Peverley
Todd White (4)
Assist: Slava Kozlov
Tobias Enstrom (4)
Assists: Ilya Kovalchuk, Bryan Little
Bryan Little (6)
Assists: Jim Slater, Ondrej Pavelec