With the Panthers’ season on the line against the visiting Lightning, coach Joel Quenneville figured “we’ve got nothing to lose.” So, he bet everything on 20-year-old rookie goalie Spencer Knight with four games of NHL experience and none in the playoffs.

Jackpot!

The Panthers beat the Lightning 4-1 in Game 5 at BB&T Center on Monday night, forcing a Game 6 in this first-round series Wednesday in Tampa thanks to Knight’s sterling performance in goal.

The youngest netminder to ever make his NHL playoffs debut in a potential elimination game, Knight made 36 saves, stealing a victory in a way neither two-time Vezina winner Sergei Bobrovsky nor Chris Driedger could while each started two of the previous four games.

“He won the game for us,” Panthers captain Sasha Barkov said.

The former Boston College standout became the second-youngest goalie to win his first NHL playoff game and the fifth youngest to start and win any playoff game.

“You didn’t see any nervousness from him,” Barkov added. “He’s a special kid. You don’t see that often. He’s so young. He’s so calm, confident [and] technically, really good. I could be here ‘til tomorrow if you want me to say everything about Spencer.”

“It’s a fun confidence that he has,” Quenneville noted. “He’s one of those guys that’s composed in a lot of ways. Nothing really gets him off kilter.”

Not even allowing a goal on the first shot from the Lightning, just 53 seconds into Game 5.

Ross Colton scored on a 2-on-1 rush, and you wondered if everything would quickly go downhill for Knight and the Panthers.

Instead, the early Lightning goal actually helped Knight settle in.

“Once you let one in, you just reset and say, ‘All right, well, this is how it’s going to go.’ You can’t do anything to change it. ‘Let’s just go play now,’” Knight said. “I just tried to recover after that, smile and have fun.”

He kept smiling the entire night — CNBC’s cameras continually showed his huge grin through his goalie mask — even as the Lightning continued to pepper him with shots.

They fired 22 on goal in the first period. He entered intermission with the second-most saves in a period in Panthers playoff history.

“He was a rock back there,” defenseman MacKenzie Weegar said.

“We came into the room thinking, ‘Boy are we lucky,’” Quenneville said of his team’s 1-0 deficit after one period. “Spencer put on a clinic and gave us a chance. That was our worst period in a long time.”

Said Knight: “I’m not really thinking much about the score, what I’ve given up, what’s coming at me. I just kind of react. …Don’t think about the result. Detach from it, and just have fun in the moment.”

Everything Quenneville said he had seen from Knight leading up to his decision to start the youngster led him to believe that Knight could handle the pressure.

His teammates felt the same.

So, when Knight found out Sunday that he’d be in net, they were excited for him, Barkov said.

“We trust him,” Barkov added. “We enjoy playing in front of him.”

Buoyed by Knight’s ability to limit the Lightning to a single goal in the first period, the Panthers scored a pair in the second.

Weegar fired in a shot off a face-off win at 6:19 and Mason Marchment gave the Panthers the lead with 3:05 left before intermission.

Then 35 seconds into the third period, Barkov’s shot went in off Patric Hornqvist for a power-play goal and 3-1 lead. Hornqvist also picked up an assist on Frank Vatrano’s empty-netter with 15 seconds left.

Barkov had two assists, as did Jonathan Huberdeau, whose 10 points in this series are the most ever by a Panthers player in a playoff series and lead the NHL this postseason.

After not giving Knight any assistance in the opening period, the Panthers held the Lightning to 15 shots on goal combined in the second and third periods.

They played disciplined all night, staying out of the penalty box. They took just two penalties — both in the first period — and killed off both.

You could sense the Panthers’ desperation in this must-win Game 5 from the outset. And the fans, also aware what was at stake, provided an atmosphere that was “absolutely electric,” Weegar said.

“They [played] a big part tonight in keeping us in the game, really giving us momentum,” he added. “It was by far the best arena [atmosphere] I’ve ever been in since I’ve been here.”

Officially, the increased capacity attendance at BB&T Center on Monday was 11,551, though “it felt like at least 24 or 25,000,” Barkov said. It’ll be even more electric if the Panthers can force a Game 7 of this Sunshine State Showdown.

As you would expect, Knight will get the call again in net for Game 6.

He’s set a high bar of expectation for himself after his incredible playoff debut Monday.

And it was all made possible by Quenneville’s bold move.

Steve Gorten, columnist for Florida Hockey Now, has covered the Florida Panthers for the South Florida Sun-Sentinel and the Columbus Blue Jackets for the Columbus Dispatch.

Follow him @sgorten

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