Lighting the lamp for the 18th time this season, Anthony Duclair broke the ice early in Seattle when his shot from the right circle, after being kicked out by Philipp Grubauer, took a fortuitous bounce off a defender and into the net to give the Panthers a 1-0 lead at 4:57 of the first period.
Pulling the Kraken even, Marcus Johansson, who entered the night with four goals in his career against Florida, teed up a pass from Mark Giordano in transition and blasted a shot over Sergei Bobrovsky's glove from the left circle to make it a 1-1 game five minutes into the second period.
Moments after coming up short on a 5-on-3 power play, the Kraken took their first lead of the game when Yanni Gourde sailed a shot past Bobrovsky at 10:02 to make it 2-1. Extending that lead to 3-1 in a hurry, a bouncing puck then went off Colin Blackwell and into the cage at 10:19.
"You could feel it coming from the first period on," Panthers interim head coach Andrew Brunette said of Seattle's offensive push in the middle frame. "Bob was keeping us in the game, and we didn't handle the pressure very well. We were flat a little bit again tonight."
Catching fire on the power play, which is operating at over 30% since the holiday break, the Panthers cut into their deficit just over two minutes later when Jonathan Huberdeau took a pass from Aaron Ekblad and wired home a short-side shot from the point to make it 3-2 at 12:32.
Tying the game in the blink of an eye, Huberdeau flew down the ice along the right boards, made a hard cut and sent a no-look pass to Barkov for a quick goal to make it 3-3 at 14:07.
Regaining the lead for the Kraken, Mason Appleton received a nifty cross-ice pass from Alex Wennberg and ripped a shot into the twine just 26 seconds into the third period to make it 4-3.
"Our intensity picked up there," Brunette said. "We kind of got mad and got going for a little while. It felt like we took the game over and starting to do the things we needed to do, and then we started the third period. … We had a breakdown, they scored, and we had to chase."
Looking for the game-tying goal after pulling their goaltender with just over two minutes left in regulation, the Panthers fired off a flurry of shots toward Seattle's net, but Grubauer held his ground until Calle Jarnkrok scored an empty-netter to make it 5-3 with only 19 seconds left.
Despite tonight's loss, the Panthers, who have won 10 of their last 13 games, remain in first place in the Atlantic Division with a record of 28-9-5, while the Kraken, who won both of their games against Florida this season, sit at 13-24-4 after winning two of their last three games.
"They're proud," Brunette said of Seattle's play tonight. "They want to prove that they're for real and that they're better than their record. We weren't prepared for the storm that was coming."
Splitting the first four games on their five-game road trip, the Panthers will look to end their trek on a high note when they visit Winnipeg on Tuesday. When asked about the key to coming out on top in that matchup, Brunette and Barkov both pointed to the same thing: a better start.
"We just need to start better," Barkov said. "We need to get ready mentally and physically."
Here are five takeaways from Sunday's loss in Seattle…