Florida outshot Dallas 29-4 in the second period.
"We just fell apart," Stars defenseman John Klingberg said. "It's sports, it happens, but it's not acceptable the way it happened. Just shift after shift we just cracked everywhere. We're not in the right spots and we turned the puck over in the wrong places all the time. We get long shifts out there, so we have to ice it or chip it out and we have to stay out even longer, so it's a bad circle."
Barkov scored an empty-net goal with 28 seconds remaining for the 3-1 final.
The Panthers are 5-0-0 after a loss this season.
"We're a resilient team this year," defenseman MacKenzie Weegar said. "A lot of competitors in the room. It's fun. We're bouncing back well, and that's what we need to do to be a really good team in this league."
NOTES: The Panthers had 28 shots on goal in the second period of a 3-2 win against the Washington Capitals on Oct. 20, 2005. Their 29 shots in the second Monday are tied for the eighth-most in one period in NHL history. The Tampa Bay Lightning hold the record (33 in the second period of a 6-3 win against the Chicago Blackhawks on Oct. 21, 2018). ... Florida has an NHL-high nine comeback victories this season, one more than the Pittsburgh Penguins. … Khudobin's 49 saves tied his NHL high, set Dec. 27, 2018, in a 2-0 victory against the Nashville Predators. … Linesman Devin Berg left the game in the second period after being hit by a puck.