Barzal's goal came after Morgan Rielly tied it 3-3 for Toronto with seven seconds remaining in regulation. John Tavares, who played his first nine seasons with New York (2009-18) after being the No. 1 pick in the 2009 NHL Draft, earned his 1,000th point on the play with the primary assist.
“It's been a great ride so far, a great journey,” Tavares said. “Obviously, you want to celebrate in a win, but I'm very proud of it and, in certain ways, just kind of happy it's happened.
“The uniqueness of doing it where I played my first nine years of my career and a big part of who I am and the way this place impacted me, it was tremendous. So, really unique and cool to do it here.”
Brock Nelson and Kyle Palmieri each had a goal and an assist for the Islanders (13-7-7), who have won three in a row and are 5-0-1 in their past six games. Ilya Sorokin made 37 saves.
“We did face some adversity," New York coach Lane Lambert said. "I thought, for the most part in the third period, we played the game we wanted to play. They pulled the goalie. They've got a lot of skill, and they ended up tying the hockey game, but we found a way, and that's what good teams do.”
Tavares had a goal and an assist, and William Nylander had two assists for the Maple Leafs (14-6-5), who extended their point streak to six games (4-0-2). Ilya Samsonov made 25 saves.