This was the difference between a team with everything to play for and a team playing for nothing.

For most of two periods, the Thrashers controlled the game against the Capitals, who are fighting for their playoff lives. But Washington stayed alive in their desperate bid for the postseason by scoring four times in the third period to defeat the Thrashers 5-3.

JOHN AMIS/AP (ENLARGE)

Washington Capitals defenseman Steve Eminger (44) checks Atlanta Thrashers right wing Mark Recchi, left, to the ice during the first period.

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How bad was it for the Thrashers in the third?

They were outshot 23-2 as the Capitals kept relentless pressure on Thrashers goalie Kari Lehtonen, who finished with 39 saves but faced more shots in the final period than opposing goalie Cristobal Huet saw all game.

"When we get a nice lead, we should just keep playing the same way," Lehtonen said. "I don't know what changed so much going into the third. It's just embarrassing."

After Backstrom's second goal of the third period, he was mobbed by Alex Ovechkin and other teammates in the corner as they jumped up and down to celebrate what turned out to be the game-winning goal.

Lehtonen slammed down his stick and his blocker went with it while Washington celebrated. He followed that by kicking the blocker before teammate Garnet Exelby picked it up and handed it back to him.

Lehtonen's frustrations are becoming increasingly public.

"It's not too many times this year when I've been having the opportunity to enjoy a win. Just taking it away like that is frustrating," Lehtonen said. "It's just weird to see how great we can play and how terrible we can play in the same game."

The greatness came during a stretch in the second period when the Thrashers scored three unanswered goals, including two from Jim Slater.

Eric Perrin set up both of Slater's goals with impressive assists. The first came short-handed when Perrin intercepted an Ovechkin pass, spun and found Slater streaking up the middle of the ice for a breakaway on Cristobal Huet.

Slater beat Huet to give Perrin his league-leading eighth short-handed assist of the season.

"Anytime you're short-handed and there's a turnover up at the blueline, you want to bust through the middle there," said Slater who now has six goals this season. "[Perrin] knew that; it was a perfect pass by him."

Enstrom scored the Thrashers' first goal of the game on a slapshot from the slot on the power play. The goal was Enstrom's fifth of the season and his 38th point of the season, which ties Jaroslav Modry for the most in franchise history by a defenseman.

But it hardly mattered after Washington seized momentum in the third following Ovechkin's 60th goal of the season and second of the game. He has now scored 16 goals on Lehtonen, the most on any goalie in the league.

Five minutes later, Backstrom was scoring his second, and the comeback was finished —just another Thrashers loss in which they couldn't maintain a high level of play for an entire game.

"We've been having a hard time, pretty much the whole year, putting 60-minute games together," Holik said. "At least that's one thing we're consistent with; we can't play a 60-minute game."