Tsyplakov tied the game 2-2 at 12:16, beating Vanecek five-hole on a breakaway.
Dobson scored just 17 seconds later to give the Islanders a 3-2 lead. He stepped in front of a pass from Uvis Balinskis in the neutral zone, skated down the left wing, and cut inside on Seth Jones before lifting a shot over Vanecek's glove.
Sorokin preserved the lead with 36 seconds remaining by sprawling out to deny a rebound opportunity from Reinhart with his right pad.
Holmstrom then scored into the empty net with seven seconds left for the 4-2 final.
“It was nice to see that comeback,” Islanders coach Patrick Roy said. “I thought we played really well for 40 minutes and we were down 2-0. Seeing our guys be resilient and find a way to get some goals made me really proud of them, because they work hard. It’s fun to watch. ... That’s exactly who we are, that’s who we have been for a while now. I’m very proud of this group, especially tonight.”
Reinhart gave the Panthers a 1-0 lead at 1:00 of the second period. Barkov got the rebound of Gustav Forsling’s point shot in front and sent a short backhand pass to Reinhart, who scored past Sorokin's right pad from near the left post.
Barkov extended the lead to 2-0 at 4:48 of the second. Reinhart’s wrist shot from the right circle hit Barkov in the midsection and fluttered over Sorokin with one second remaining on a power play.
“We have to be better, especially in third periods, especially when we have the lead,” Barkov said. “We have to play better. So, that’s on us. ... I think we need to just stick to our game plan. I think we were just trying to defend the whole period. We need to be able to play our own game, like a whole 60 minutes, not just 40 minutes. We need to stay on the puck, play with the puck, and be confident enough to play with the puck.”