Florida goalie Roberto Luongo made 26 saves becoming the third goalie in NHL history to play 1,000 games (Martin Brodeur, Patrick Roy) and the first to win his 1,000th game.
"I was feeling a little bit sluggish today for some reason but, tell you what, the boys probably played their best game of the year," Luongo said. "I thought they were phenomenal both ends of the ice. I think that was our best game by far. They didn't really have any chances at all. That's the best gift the boys could have given me."
Jared McCann gave Florida a 3-2 lead with 5:37 remaining in the third period when he tipped Mike Matheson's wrist shot from the point.
McCann scored skating with the top line after center Aleksander Barkov left the game in the third period with an upper-body injury.
"It's crazy," Luongo said. "Just kind of like it was meant to be, right? The last few months we've been finding ways to win no matter what the situation is. That's another example right there where [one of] our top players goes down and [McCann] steps right up, first shift, boom, scores the game-winner. It says a lot about our club."
Barkov gave the Panthers a 1-0 lead at 7:42 of the first period with his 100th NHL goal. He tipped Evgenii Dadonov's backdoor pass from the bottom of the right face-off circle. Barkov left the game with 6:45 left in the third period after being checked into the boards by Colby Cave.
Frank Vatrano made it 2-0 at 9:34 of the first after a turnover behind the Boston net when he put a backhand past Tuukka Rask.
Ryan Donato made it 2-1 at 15:19 with a power-play goal 14 seconds after Mike Matheson was called for holding. Torey Krug's shot from the point hit Donato in the upper body.
Danton Heinen tied it 2-2 at 2:11 of the second period after a turnover in the Florida zone. He took a centering feed from David Krejci and beat Luongo with a wrist shot to the blocker side.
"We came out strong," Luongo said. "We played for a full 60 minutes. We didn't have any letdowns. Just a complete hockey game against a really good team. I'm proud of the guys, the way they worked hard tonight. Made my job a lot easier."