The Islanders’ dogged work for the opening 10 minutes of the second period helped make good on Roy’s promise on Saturday night. They scored three goals during that stretch — those goals the result of won battles, races, and every inch of contested ice — to fuel a 6-3 win over the Penguins at USB Arena in Elmont, N.Y.

Duclair gave the Islanders a 2-1 lead at 5:39 of the middle frame off the rush. Kyle Palmieri collected a puck just inside the Penguins’ zone before he found Duclair cutting toward the low slot on an odd-man rush for a finish past Jarry’s blocker.

Nobody said it outright in the lead up to the first of a back-to-back, home-and-home matchup with the Penguins on Saturday, but winning this set of games — or at least avoiding a sweep — was as essential a task as the Islanders have faced all season.

After a four-day layoff, the Penguins struggled to find a good rhythm. Good moments were followed by bad, and pucks were just out of reach for prime scoring chances.

The Islanders come out firing in the second period with goals from Anthony Duclair, Anders Lee and Casey Cizikas giving them a 4-1 lead over the Penguins.

The Pittsburgh Penguins (16-15-5) hit the NHL holiday break with a chest-thumping win over their rival Philadelphia Flyers on Monday. Their Metro Division swing continues Saturday when they visit the slowly backsliding New York Islanders (13-15-7) at UBS Arena.

The Islanders made amends of sorts for their pre-Christmas break implosion at the hands of the 13-game-slump-breaking Buffalo Sabres by opening their post-break schedule with a satisfying 6-3 win over the Pittsburgh Penguins.

The New York Islanders return from the holiday break a mess. Their Dec. 23 must-win game against the hapless Buffalo Sabres ended in a 7-1 loss. At 13-15-7, the Islanders have the worst record in the Metropolitan Division and the fourth-worst in the Eastern Conference.