NASHVILLE -- Let up for a second and it will cost you.

The Thrashers have yet to fully learn that lesson this season.

Nashville scored three first-period goals en route to a 6-3 victory over the Thrashers on Tuesday night at Bridgestone Arena. All three opening goals came during a lapse by the Thrashers in their own zone.

“I thought we played a real good game but when we made a mistake, it was a big one,” Thrashers coach Craig Ramsay said. “It wasn’t a little mistake, it was something costly. … Everything that could have gone wrong did in that one short stretch.”

The Thrashers (33-34-12, 78 points) have three games remaining in a non-playoff season that has been punctuated by such problems. They have made the postseason just once in the franchise’s 11-year history. The Predators (43-26-11, 97 points) will clinch their sixth playoff berth in the past seven years with a point in their final two games or a Dallas loss.

The Predators opened the scoring 5:24 into the game on a goal by Matt Halischuk. Entering the offensive zone, the puck tipped off Tim Stapleton’s stick along the board and deflected to Halischuk. Despite being fronted by Thrashers defenseman Andrey Zubarev, Halischuk shoveled a back-handed shot that beat goaltender Chris Mason.

And then the issue that has plagued the Thrashers all season presented itself again -- twice.

They allowed back-to-back goals with less than a minute left in the period. Jordin Tootoo tapped in a puck that trickled around Mason and into the crease with 41.9 seconds left. Sergei Kostitsyn would wrist a shot past Mason with eight-tenths of a second left for the three-goal margin.

When Tootoo scored 1:56 into the second period, chasing Mason and bringing in Ondrej Pavelec, it marked the 26th time this season that the Thrashers allowed an opponent back-to-back goals in under two minutes. Kostitsyn’s goal was the eighth time it happened in 41 seconds or less. The defensive pairing of Mark Stuart and Zubarev, making his NHL debut, was on the ice for the first four goals.

“It was boom, boom, boom,” Stuart said. “It happened pretty quick. … [On the second two goals] we have to do a better job of finding guys in front of the net and we didn’t do that.”

Kostitsyn scored his second of the game 2:28 into the third period adding to the rout.

Blake Wheeler scored 38 seconds later for the Thrashers to avoid the shutout, wristing a shot past Predators goaltender Pekka Rinne. Wheeler scored again with 3:35 remaining. The goals leave Wheeler with 18 on the season and seven in 20 games with the Thrashers. Nik Antropov scored his 16th goal of the season 45 seconds later to extend his point streak to five games (three goals, two assists).

“We out shoot them, out skate them, out play them and in the matter of less than a minute they have two more goals,” Antropov said. “It kills big time.

“I’ve never seen this team quit. Not once this year. We tried to battle back but it was too big of a deficit. It’s a good sign. There are warriors in this room.”

Mike Fisher added a third-period power-play goal at the 6:19 mark for the Predators. It came with Eric Boulton in the box on a two-minute roughing and a 10-minute misconduct penalty. The goal snapped a streak of 18 consecutive penalty kills for the Thrashers over the past seven games.

The Thrashers controlled the play for much of the game, finishing with a 36-24 shots-on-goal advantage.

“If we want to win the game we have to play all 60 minutes,” Pavelec said. “Who cares if we played better in the third or the second? That’s not how we are going to win the game. We put ourselves in this situation. We can’t feel sorry for ourselves. It’s the NHL and we have to play as hard as we can, try to win and build something for next year.”

The Thrashers play at the New York Rangers on Thursday before returning home for the final two games of the season. They play host to Carolina on Friday and Pittsburgh on Sunday.

Etc.

Defenseman Tobias Enstrom suffered a shoulder injury Saturday against Boston. The injury prevented Enstrom from traveling for Tuesday’s game and will do the same for Thursday’s game. ... In Enstrom’s absence, Stuart replaced him as alternate captain. ... The Thrashers signed 2008 draft pick Zach Redmond to an entry-level contract. The seventh-round pick (No. 184 overall) recently concluded his senior season as a defenseman for Ferris State. Redmond, 22, will report to AHL Chicago.