ST. LOUIS -- Being the eighth seed in the Western Conference playoffs, the Nashville Predators knew they would have overcome different levels of adversity if they want to keep advancing in the playoffs

They did just that on Wednesday night in Game 1 of their second-round matchup against the St. Louis Blues.

Vernon Fiddler scored with 5:05 left in the third period, after the Blues had rallied from a 3-1 deficit to tie the game, giving the Predators a 4-3 win and keeping them undefeated in this year's playoff run.

"They had a little push there," Fiddler said. "The building was rocking. You have to give our guys credit. We just regrouped and went back at them."

Fiddler's goal came after the Blues failed to clear the puck out of their zone, with goalie Jake Allen unable to poke-check the puck away from Fiddler.

"Just a little mistake by me," Allen said. "It cost us."

Fiddler was playing his first game in this year's playoffs after sitting out the four-game sweep of the Chicago Blackhawks in the opening round.

"It was just a quick transition," Fiddler said of the play and the goal. "I saw (teammate Austin) Watson kind of get it in his feet outside and just tried to get to the net. He made a little flip pass, and I just got a piece of it and just chipped it over the goalie. Lucky one."

P.K. Subban had a goal and two assists for the Predators, his second career three-point playoff game, and led the way as Nashville got past a more serious moment in the second period.

Just 1:46 into the period, the Predators watched 20-year-old left winger Kevin Fiala be placed on a stretcher and taken off the ice with an apparent serious injury after he slid hard into the boards at an awkward angle following a hard hit from Blues defenseman Robert Bortuzzo.

Just 36 seconds after play resumed -- following a delay for an ambulance to arrive at Scottrade Center -- Subban's goal scored to put the Predators in front 2-0.

"It was tough," Subban said. "You never want to see a young kid go down like that and be taken off on a stretcher. I've experienced it before and it's not fun, especially for your family and friend so we hope he's OK."

The Predators said Fiala was alert and stable but offered no other report on his condition after the game.

"I thought we got tested tonight in different ways and really responded well to all of it," Nashville coach Peter Laviolette said. "We knew it was going to be a tough game, a physical game. I don't think anybody could have thought or planned for an incident like that with Kevin. Yet, our guys you could hear them on the bench when it happened and making sure their next shift was going to be a good one for Kevin.

"It was just one of those unfortunate incidents that happened in the game and I like the response from our guys not only there, but once they tied it up. I thought it was just a gutsy effort from that point to get back to work in the offensive zone and a huge goal by Vern to get us on top."

The Blues cut the Predators lead to 2-1 later in the second period on a goal from Colton Parayko, but a second power-play goal, this one from Filip Forsberg, restored the two-goal lead. Nashville also got a power play goal from Colin Wilson, deflecting a shot by Subban, in the first period.

The Blues got even in the third period on goals from Jaden Schwartz and Vladimir Sobotka, testing the Predators' response to adversity again.

"For a group that maybe doesn't have the most playoff experience through our lineup we seem to show a lot of composure and I think it was tested again today," Subban said. "We're going to be tested more, much more especially in this series. That is a good team in there and they compete so hard and they're hard in the puck and those are some of the toughest battles that I've ever been in my career. So I expect we'll need even better in Game 2."

The Blues were called for three penalties in the second period, giving the Predators all of the momentum in the game at that point.

"We dug ourselves a hole in the second period and I liked the push back and the fact we came out the way we did (in the third period)," said Blues coach Mike Yeo. "There are some things we can learn from that but the reality is the second period was not good enough and ultimately it cost us the game.

"You get to this time of the year and it's such a fine line that you have to be a little more disciplined and find a way to make sure you are not putting yourself in the box more than the other team."

NOTES: Wednesday night's game was the 360th postseason game in Blues' history, but their first against the Predators. ... In addition to LW Colin Wilson and LW Vernon Fiddler, LW Cody McLeod was inserted into the Predators' lineup. McLeod hadn't played in the first round against the Blackhawks. ... The Blues kept the same lineup they used in Game 5 against Minnesota, meaning healthy scratches were RW Dmitrij Jaskin, C Ivan Barbashev and LW Zach Sanford. ... Scratches for the Predators included RW Craig Smith, C Calle Jarnkrok, LW Harry Zolnierczyk and LW Pontus Aberg.