Sam Reinhart and Carter Verhaeghe each had a goal and an assist, and Spencer Knight made 19 saves for Florida (15-14-4).
"I don't think our game was a whole lot different until it got to about 6-3," Panthers coach Paul Maurice said. "I think we had things that we'd like to do better with the pucks in the transition game. That kind of bit us in the butt, but we put up 39 [shots]. We had enough to score; we gave up more than we could tonight to have a chance to win."
The Bruins took a 4-0 lead, propelled by three first-period goals in a 5:16 span, but Florida followed up with three goals in 5:20 in the second period to make it 4-3 before Boston pulled away.
"It's going to happen," said Bergeron, the Bruins captain. "I think we need to realize what makes you kind of fall back like that and give up the goals, or the odd-man rushes or the situation. I think, to me, it's always been simplifying, and when you make the hard play instead of making the simple play or the easy play, I think that's when you kind of get caught."
Connor Clifton gave Boston a 1-0 lead at 10:51 of the first period when he brought the puck into the zone and cycled around the net to collect his own centering pass that Knight deflected and shot bar down.
Carlo made it 2-0 at 14:04, streaking into the high slot and firing off a pass from Marchand to end his 32-game goal drought.
"I feel like there's been a lot of opportunities in the offensive zone for all of us defensemen," Carlo said. "It's a matter of, you know, putting it in the back of the net."