LAS VEGAS -- The Vegas Golden Knights are no longer the new kids on the NHL block.

They're a perennial powerhouse.

Jonathan Marchessault scored twice, and the Golden Knights became the first NHL team to clinch a playoff berth, beating the San Jose Sharks 5-2 Wednesday night for their eighth straight victory.

Vegas, which leads the NHL with 33 wins and 68 points, also became the fourth franchise in NHL history to make the playoffs in each of its first four seasons. The Golden Knights lost to the Washington Capitals in the 2018 Stanley Cup Final in their inaugural season.

"It's an accomplishment in this league; 31 teams to make the playoffs," said Peter DeBoer, who has led two teams to Stanley Cup Final appearances during his coaching career. "What this franchise has done so far is unheard of. I don't know if you'll ever see that again out of an expansion team.

"I wouldn't trade our group for any other group out there."

The Golden Knights improved to 15-1-3 all-time against the Sharks in regular-season meetings, including a perfect 7-0-0 this season. Vegas also improved to 18-4-2 at home.

"We've been doing good against [San Jose]," Marchessault said. "We seem to be playing the right way. It's good to have success against a divisional team like that."

Mark Stone, Alex Tuch and Mattias Janmark also scored for Vegas. Marc-Andre Fleury made 31 saves to improve to 5-0-0 against the Sharks this season and 7-0-1 in his last eight.

"They're scoring every night, and they're looking dangerous doing it," DeBoer said of his team's offense. "That for me is what we're looking for, even on nights when the pucks don't go in, we're creating momentum, we're getting chances, we're putting pressure on the other team."

Timo Meier and Tomas Hertl scored for San Jose, which is now mired in an 0-6-1 slide. Josef Korenar made 35 saves.

The Sharks took a 2-1 lead just past midway through the second period before the Golden Knights scored four unanswered goals.

"The hottest team in the league, it's not just us," San Jose coach Bob Boughner said. "We're a team that doesn't match up on paper to them. So a lot of things have to go right for us. They find ways to win. Our power play has to get going, it's been dry for a while. That's the difference in these tight games. You have to have good special teams when you go against these guys."

The Sharks were 0-for-3 on the power plays against the league's second-best penalty kill.

On the power play, Pacioretty fed Stone, who wrapped the puck around Korenar to knot the score 2-all with 7:08 left in the second period. It was Stone's team-leading sixth power-play goal of the season, while Pacioretty became the 10th active U.S.-born player to collect 600 career points.

Tuch blasted home the go-ahead goal with 50 seconds left in the second, giving Vegas its first lead of the game.

Marchessault netted his second goal and third point of the night when he beat Korenar short side, extending Vegas' lead to 4-2 with 6:42 left in the game.

Janmark, who was acquired from Chicago at the trade deadline, scored an empty-netter for his first as a Golden Knight with 56 seconds to go.

"I liked our resiliency, I liked our calmness tonight," DeBoer said. "I thought after the first period, we could've been up three. We stuck with it. We took some penalties we found to kill off, get some big saves at the right time. There wasn't any panic there."