Nelson gave the Islanders a 1-0 lead at 12:11 of the first period, stealing the puck from Ben Chiarot and shooting past Lyon from the low slot.
Casey Cizikas made it 2-0 at 16:18, deflecting Adam Pelech’s shot past Lyon.
Maatta cut it to 2-1 at 5:04 of the second with a slap shot from the left circle.
Patrick Kane tied it 2-2 10 seconds into the third period, extending his point streak to 10 games (15 points; six goals, nine assists).
“Everyone makes a big deal about letting leads go, but it happens when you have leads,” Roy said. “A one-goal lead in this league is nothing. Even a two-goal lead in this league is nothing.”
Nelson put the Islanders back ahead 3-2 at 5:04 with a power-play goal from the bottom of the right circle.
Maatta scored his second of the game to tie it 3-3 at 10:49, shooting into an open net off a cross-ice pass from Shayne Gostisbehere. It was Maatta’s third multigoal game in the NHL (March 1, 2018, against the Boston Bruins and March 6, 2014 against the San Jose Sharks).
“I think we’re doing a really good job of using our defensemen in a five-man unit to get them some chances,” Maatta said. “[David Perron] made a great pass to get me the puck for the first one, and [Gostisbehere] made a great pass for the second one.”
Barzal gave New York a 4-3 lead at 13:58 when his shot from a sharp angle banked in off Lyon.
“I think this has to go down as a disappointing missed opportunity,” Lalonde said. “We had the game tied twice in the third period and didn’t get a point. The Islanders are too good of a team to give them 20 minutes like we did in the first period.”