Panthers score last-gasp goal to beat Hurricanes and reach Stanley Cup final
Tkachuk ensured the Panthers will advance to the National Hockey League's championship series for the first time since 1996 after rifling home with just 4.3 seconds remaining to seal a 4-0 Eastern Conference finals sweep.
Tkachuk's goal – his third game-winner of the series – was the final act of a pulsating contest at the FLA Live Arena in Sunrise.
Carolina, who had trailed 2-0 in the first period, thought they had done enough to force overtime after Jesper Fast levelled it at 3-3 with just over three minutes remaining.
But Florida launched a furious late onslaught and deft play by Tkachuk led to his late winner amid incredible scenes.
Earlier, Anthony Duclair got the Panthers' off to a dream start, firing the home side into a 1-0 lead after just 41 seconds following a goalmouth scramble.
Carolina's problems went from bad to worse moments later when key defenseman Jaccob Slavin was knocked out of the contest after a hit from Panthers forward Sam Bennett.
Slavin was attempting to play out from behind his own net when Bennett poleaxed him with a check that flattened the Carolina player.
Slavin, whose head struck the boards as he crashed to the ice, attempted to get up but fell over before being helped off.
He was subsequently ruled out of the remainder of the game with an upper-body injury.
Tkachuk then made it 2-0 to the Panthers after 10min 23sec of the first period with a power play goal.
Carolina responded superbly and were thrown a lifeline after 13 minutes when Paul Stastny pulled a goal back, bundling a rebound after a long-range effort from Brady Skjei.
Teuvo Teravainen then put Carolina on level terms early in the second period, guiding the puck past Sergei Bobrovsky for 2-2.
Ryan Lomberg put the Panthers back in front and it looked as if the lead would hold until Fast's equalizer stunned the hosts before Tchahuk's sensational late winner.
Florida will play either the Vegas Golden Knights or the Dallas Stars in the Stanley Cup final. The Golden Knights lead their series against Dallas 3-0.