Tkachuk scored twice in the third period, including the tying goal with 13 seconds remaining. He then won it at 2:23 of overtime with a wrist shot from the left hash marks.
The goal gave him seven points (six goals, one assist) in his past two games. He had four points in a 7-3 win at the Columbus Blue Jackets on Tuesday.
Seth Jones had two assists, both on Florida’s final two goals, and Akira Schmid made 15 saves in his second straight win for the Panthers (4-2-2).
Liam Ohgren and defenseman Elias Pettersson scored, and Leevi Merilainen made 36 saves for the Canucks (2-6-1), who have lost six straight (0-5-1).
Vancouver took a 1-0 lead at 7:23 of the first period on its first shot of the game after Florida failed to clear the puck. Linus Karlsson got the puck at the top of the zone and fed it through traffic to a wide-open Ohgren near the right face-off circle, and he scored with a skipping shot from above the hash marks through the five-hole.
Pettersson made it 2-0 at 17:06 during 4-on-4 play. Filip Chytil, in his season debut after sustaining a shoulder injury in the preseason, sent a pass from below the goal line to a waiting Pettersson in the slot, where his one-timer sailed past Schmid.
The Panthers finally scored on their 32nd shot of the game at 11:11 of the third, Tkachuk making it 2-1 with a wrist shot from above the right circle off an Aaron Ekblad pass.
With Schmid pulled for the extra attacker, Tkachuk tied it 2-2 at 19:47. He one-timed a Carter Verhaeghe pass in the right circle, scoring off the far post.
