Kyle Okposo scored a hat trick after the Islanders opened a commanding early lead with three first-period goals as New York routed the last-place Edmonton Oilers 8-1 on Sunday.

Thomas Greiss made 30 saves for the Islanders (27-18-6), who moved within three points of the Rangers for second-place in the Metropolitan Division.

Johnny Boychuck, John Tavares and Nikolay Kulemin scored in the opening period, chasing former Islanders netminder Anders Nilsson, who was replaced after Kulemin's goal by former Ranger Cam Talbot.

Boychuk, in his first game back after missing 11 games with an upper body injury suffered on Dec. 31 at Buffalo, ripped a slapshot past Nilsson at 2:57 for his fourth goal of the season.

Tavares made it 2-0 at 9:12 with his 19th goal before Kulemin added his sixth at 11:24. Oilers coach Todd McLellan then pulled Nilsson, replacing him with Talbot. Nilsson stopped only seven of the 10 shots he faced.

Okposo made it 4-0 at 2:32 of the second, then scored again at 6:09 of the middle period.

After Oilers rookie sensation Connor McDavid finally put Edmonton on the board with his seventh goal at 6:50, Josh Bailey made it 6-1 at 9:36.

Cal Clutterbuck increased the margin to 7-1 at 16:04 of the middle period with his 11th goal with an assist to linemate Casey Cizikas. Talbot raised his arms in frustration after Clutterbuck's goal, seemingly exasperated with the defensive effort in front of him.

Okposo completed his hat trick at 7:27 of the third, when he whipped a shot on the power play past Talbot for his 15th goal of the season. The goal making it 8-1 for the home team led to a cascade of hats tossed onto the Barclays Center ice.

The 19-year-old McDavid — the first overall pick in last June's draft - returned after missing 37 games with a broken collarbone for the opening game of the Edmonton's four-game road trip. McDavid scored once and added two assists in a 5-1 win at Columbus, then had two assists in a 7-2 victory at Ottawa.

Defenseman Nick Leddy had three assists for the Islanders while forwards Frans Nielsen and Tavares each had two.

Playing his first game since Jan. 12, Greiss was his usual stellar self. He didn't have an especially tough game despite the litany of offense skill on the Oilers roster in addition to McDavid.

Other former first overall picks Taylor Hall and Nail Yakupov were essentially invisible as Greiss improved to 14-6-2 this season, his first with the Islanders.

They improved to 17-8-3 at Barclays Center in their first season in Brooklyn after 43 years at Nassau Coliseum.

The Oilers haven't won in New York against the Islanders since Dec. 14, 1999, when he beat the Islanders 4-2 at Nassau Coliseum.

NOTES: Former Islander Griffin Reinhart played against the team that drafted him fourth overall in 2012 for the first time . The teams meet again in Edmonton on Feb. 28.