LAS VEGAS — Jonathan Marchessault and William Karlsson have struggled to find the back of the net since Dec. 22, scoring a combined three goals over 12 games.

Vegas’ dynamic top-line forwards topped that Saturday night.

Marchessault scored three goals for his second career hat trick and Karlsson got his 16th of the season to help lead the Golden Knights to a 7-3 victory over the Pittsburgh Penguins.

“Our first period we weren’t necessarily happy; as a line we take a lot of pride playing well defensively and we gave a little too much chances, but we played better in the second half of the game,” Marchessault said. “Hopefully (I) get going a little bit more here. It’s definitely been a tough stretch. I just want to get out there and help my teammates.”

Marchessault scored twice less than four minutes apart in the second period to give Vegas a 5-3 lead. His empty-netter with 21 seconds left in the game completed the scoring with the Golden Knights’ first hat trick of the season and third in franchise history.

Shea Theodore, Max Pacioretty and Oscar Lindberg also scored as the Golden Knights improved to 16-4-3 at home this season. Marc-Andre Fleury, who spent his first 13 seasons with the Penguins, stopped 34 shots to earn his league-leading 27th victory.

“It was fun, it was busy both sides, I wish maybe there wasn’t three goals going in the net,” said Fleury, who also leads the league with 43 starts. “It’s always weird (playing against Pittsburgh), I don’t know when it will stop. Just weird to see these guys out there, guys I practiced with every day for (13) years. It’s nice to win though.”

Phil Kessel, Dominik Simon and Sidney Crosby scored for Pittsburgh, and Casey DeSmith finished with 28 saves.

Both goalies were exceptional against two of the more high-energy offenses in the league. All 18 Vegas skaters had at least one shot, while 14 of Pittsburgh’s 18 had one shot.

“It’s a great team that you’re playing, you’re playing superstars over there,” Vegas coach Gerard Gallant said.