McCann gave the Kraken a 1-0 lead at 7:58 of the first period when he made a forehand-backhand deke at the right post.
Tolvanen extended it to 2-0 at 7:34 of the second period on a deflection in front.
The Panthers tied it with two goals in 11 seconds.
Forsling cut it to 2-1 on a power play at 8:53 with a one-timer from the point, and Tkachuk tied it 2-2 at 9:04 with a redirection of Dmitry Kulikov's shot.
It was Tkachuk’s first goal of the season.
Florida forward Sam Reinhart had a goal overturned with 11 seconds left in the second period after Seattle challenged for offside. His five-game goal and point streak ended (nine points; seven goals, two assists).
The Panthers went 3-1-0 on their first homestand of the season.
“You have to feel good at home,” Florida coach Paul Maurice said. “The road can be a real grind for us, so home has to be a good place for us. A big chunk of that is believing you are a good home team.’’
NOTES: Panthers center Aleksander Barkov had one shot on goal and played 20:12 after missing the previous game (3-1 win against the San Jose Sharks on Tuesday) with an illness. … It was the third of a four-game road trip for the Kraken, who visit the Tampa Bay Lightning on Monday.