SUNRISE, Fla. -- The team that posted the best regular-season record in NHL history, facing a team that needed to fight and claw all the way to the end just to get into the playoffs.

On paper, it was a mismatch.

On ice, it's going to Game 7.

The wild-card Florida Panthers -- by prevailing in an absolutely bonkers third period -- fended off elimination for the second time and sent the mighty Boston Bruins into a winner-take-all contest. Matthew Tkachuk scored twice, Eetu Luostarinen put Florida ahead to stay with 5:38 left and the Panthers won 7-5 on Friday night.

"Everyone's rolling. Everyone's playing. Everyone's doing the right things," Panthers captain Aleksander Barkov said. "It's fun to be a part of this, for sure."

The real fun comes Sunday: Game 7 in Boston.

"I'm going to enjoy the hell out of it," Panthers coach Paul Maurice said.

This is the seventh time the Presidents' Trophy winner will play a Game 7 in the opening round but the first since 2011. The No. 1 seed advanced in four of the previous six instances: Vancouver in 2011 against Chicago, the New York Rangers in 1992 against New Jersey, Boston in 1990 against Hartford and Calgary in 1989 against Vancouver.

Barkov, Brandon Montour, Zac Dalpe and Sam Reinhart also scored for the Panthers, who got 30 saves from Sergei Bobrovsky. Reinhart closed it out with an empty-netter with 28 seconds left -- the seventh and final goal of the third period, four of those scores by Florida.

Tyler Bertuzzi and David Pastrnak each scored twice for Boston, which got four assists from Brad Marchand and 26 saves from Linus Ullmark. Jake DeBrusk also scored for the Bruins.

Boston finished 42 points ahead of Florida in the standings this season, the biggest gap between playoff opponents in nearly 30 years. The Bruins had the best regular-season record in NHL history, and they had one-goal leads on two separate occasions in the third period -- and couldn't hold either one of them.

Not even three power-play goals and one short-handed tally was enough to give Boston a win, either.

"We worked all year to get home-ice advantage," DeBrusk said. "And it comes down to a Game 7 where we're up for elimination now."

The game started along the exact sequence that Game 5 in Boston did on Wednesday night: Florida took a 1-0 lead, Boston tied it, Florida took a 2-1 lead, Boston tied it, Florida took a 3-2 lead, Boston tied it.

Evidently, that's when the teams decided a repeat performance was boring.

They combined for four goals in a span of 6:56 -- this time, with the Panthers answering the Bruins.

"They're a determined group," Bruins coach Jim Montgomery said of Florida.

Boston went up 4-3 on a power-play score from Pastrnak, Dalpe tied it for Florida, DeBrusk scored short-handed for a 5-4 lead and Tkachuk got his second of the night 27 seconds later to tie it again.

And less than 4 minutes later, Luostarinen made it 6-5 -- the Panthers back on top with 5:38 left, a sellout crowd in Sunrise waiving white towels in unison. Boston pulled Ullmark twice with hopes of netting the equalizer, getting good looks at it in the final minute.

But Bobrovsky and Florida's defense held firm, and Reinhart finished it off. To Sunday they go, Florida on the brink of a surprise and Boston trying to avoid a collapse.

"We know that there's going to be a war out there," Ullmark said. "That's how it is in the first round. It's the toughest one to get by."

The Associated Press contributed to this report.