Sam Reinhart scored twice, Aleksander Barkov had a goal and an assist, and Matthew Tkachuk and Carter Verhaeghe each had two assists for Florida, which is the No. 1 seed from the Atlantic Division. Sergei Bobrovsky made 18 saves.
“Sometimes you want to keep the growl,” Panthers coach Paul Maurice said. “A lot of times in the playoffs it is about keeping your energy going. Cut off losses, let it go. Then there are times you want to keep it, to eat it, let it burn for a little while and find a different kind of energy source."
Reinhart gave the Panthers a 1-0 lead with a power-play goal at 2:50 of the first period. He cut to the net along the goal line and lifted a backhand under Shesterkin's right arm.
Lafreniere tied it 1-1 at 7:17, roofing a backhand over Bobrovsky's glove on a partial breakaway after avoiding a diving check by Vladimir Tarasenko.
Goodrow scored 25 seconds later on a redirection of Braden Schneider's shot from the right point to give the Rangers a 2-1 lead.
Reinhart responded with his second power-play goal of the period to tie it 2-2 at 14:46. His backdoor pass for Barkov deflected five-hole off the skate of Trouba.
“We need to move on, refocus and recover,” Reinhart said.
Lafreniere put the Rangers back in front 3-2 at 15:23 of the second period. He skated through the neutral zone and into the top of the left circle before toe-dragging Dmitry Kulikov and scoring with a backhand from in front while being knocked to the ice by Oliver Ekman-Larsson.