Huberdeau made it 4-1 at 6:54 of the third period when he finished off a 2-on-0 with Bennett after Owen Tippett stole the puck from defenseman Shayne Gostisbehere just outside Arizona's blue line.
The Coyotes cut it to 4-3 with two goals in 34 seconds. Liam O'Brien made it 4-2 at 11:57 with a shot from the right circle, and Kessel scored at 12:31.
Anthony Duclair scored an empty-net goal with 39 seconds left for the 5-3 final.
"We knew going into it, it was kind of a dangerous opponent and I think that being respectful from start to finish is part of it," Panthers coach Joel Quenneville said. "Sometimes you get ahead, you get a little careless. We got a couple of situations that we misplayed and both ended up in the net, [then] it's hockey game.
"We nailed it down at the end, but certainly don't take anything for granted in this game."
NOTES: Thornton (42 years, 115 days) became the second-oldest player in Panthers history to score a goal. Jaromir Jagr was 45 years, 45 days when he scored April 1, 2014. … Reinhart's assist was his 300th NHL point. … The Panthers became the 25th NHL team to win at least its first six games to start a season, and the first since the 2015-16 Montreal Canadiens won their first nine. … Montour had two assists. … Chychrun, who grew up in Boca Raton, Florida, led all skaters with 26:46 of ice time.