NEW YORK — Shea Theodore scored twice and added another in the shootout, former Islander Robin Lehner made 29 saves and the Vegas Golden Knights beat New York 4-3 on Sunday for their fifth straight victory.

Theodore scored on the Golden Knights’ first shootout attempt after his second goal of the game tied it with 48 seconds remaining in regulation. Nicholas Roy also scored for Vegas in the shootout.

Theodore scored his second goal of the game with Lehner pulled for an extra skater. He shot from the top of the high slot just inside the blueline. Jonathan Marchessault also scored in regulation for Vegas.

The tying goal came after Jean-Gabriel Pageau put the Islanders ahead 3-2 with 2:20 left in the third. Pageau’s goal — off a pass from Oliver Wahlstrom — sent the crowd into a frenzy a minute after they thought Cal Clutterbuck had put the Islanders ahead on a play that was ruled offsides.

Theodore put Vegas ahead 2-1 early in the third when his blast from the point on a power play eluded Ilya Sorokin, who made 31 saves.

But Islanders forward Kieffer Bellows tied it with 5:41 left after the Islanders had squandered two power-play chances after Theodore’s goal at 5:46.

The Golden Knights completed a three-game sweep of New York-area teams, having defeated the Devils on Thursday and the Rangers on Friday. Vegas also beat Boston to start the trip. The Knights have won eight of nine overall.

The Islanders also had two power-play chances to tie the contest after Theodore’s goal but couldn’t muster much against Lehner, who helped the Islanders reach the playoffs in 2018-19, his lone season with the team.

Marchessault opened the scoring at 6:56 of the first period, tapping a rebound past Sorokin for his 14th goal of the season.

Brock Nelson tied it at 11:08, beating Lehner with a low shot to the goaltender’s glove side. The goal was Nelson’s 10th of the season and his first since Nov. 20 in the Islanders’ first game at UBS Arena. Nelson missed seven games with a lower-body injury before returning on Dec. 11.

Lehner’s public acknowledgement of his struggles with depression and mental illness endeared him to the Islanders fan base. He said after beating the Devils on Thursday in Newark that he was looking forward to seeing and thanking Islanders fans in person again because they had “saved my life.”

During a short video tribute early in the first period, Lehner pointed to a tattoo in the shape of Long Island on his neck and gave the cheering crowd a thumbs up while standing near the Golden Knights bench.

The 30-year-old Lehner is 14-9-0 this season as the Golden Knights starter following the departure of Marc-Andre Fleury last summer. Since joining Vegas in a trade from Chicago in March 2020, Lehner is 30-13-2 for the Golden Knights.

MORE COVID-19 MISSING

The Islanders announced before the game that left wing Matt Martin and defenseman Robin Salo were placed in the health and safety protocol, joining center Mathew Barzal, who missed his third straight game for the same reason.

MILESTONES

Islanders defenseman Zdeno Chara played in his 1,631st NHL game, four games behind Scott Stevens among defensemen. Chris Chelios is first among defensemen with 1,651. The 44-year-old Chara is 11th overall in NHL games played … Clutterbuck played his 900th career game.

NOTES: Golden Knights captain Mark Stone was scratched with an upper-body injury … Golden Knights center Brett Howden played his 200th career games … Vegas also scratched defenseman Ben Hutton and forward Adam Brooks … The Islanders scratched forward Kyle Palmieri – who suffered lower body injury last Thursday against Boston – and continued to be without injured defenseman Ryan Pulock, who missed his 14th straight since Nov. 15 … The Islanders honored defenseman Andy Greene with a -pre-game ceremony for his 1,000th game, which he played Nov. 15 at Tampa Bay … The Islanders won the previous meeting this season, 2-0 on Oct. 24 at Las Vegas.

UP NEXT:

Islanders: Hosting Montreal on Monday night.

Golden Knights: Host Tampa Bay on Tuesday night.