Marc-Andre Fleury, making his 16th start in 17 games, finished with 23 saves to improve to 14-5-0 this season. Fleury earned his 481st career win, inching closer to Ed Belfour, who ranks fourth with 484.
Pacioretty scored in the first period and delivered a perfect backhand pass early in the third to Stone, who one-timed a wrist shot at 1:02 to make it 2-0. It ended up being Stone's sixth game-winning goal.
''A lot of times, lines are made around two guys and there's an interchangeable piece there,'' Vegas coach Peter DeBoer said. ''Stone and Patch have some chemistry; they complement each other. Big goal for us in the third period, and big power-play goal in the first.''
Timo Meier scored late for San Jose, and Devan Dubnyk stopped 34 shots.
The Golden Knights are 12-1-3 in 16 regular-season meetings with the Sharks.
Fleury put together a highlight reel throughout the game in denying San Jose skaters on four prime opportunities: Meier's breakaway in the first period; two breakaways for Evander Kane, one in the first and another in the third; and a stop against Matt Nieto, who fired a one-timer from the doorstep early in the third.
Fleury leads NHL goaltenders with a minimum 20 games played with a goals-against average of 1.77 and save percentage of .936.
''We actually had two or three chances in the first period that missed the net,'' Sharks coach Bob Boughner said. ''We had two or three more that Fleury stopped. Against a goalie like that, you have to have shot volume, second and third looks.''
With the Golden Knights returning home after a 10-day, six-game road trip, they looked sluggish as the Sharks dominated the first period.
From the opening faceoff, the Golden Knights struggled to enter San Jose's zone with possession, as the Sharks did a good job of challenging Vegas' skaters at the blue line. And when the Knights were able to dump in, they couldn't catch the Sharks, who were faster to the puck and much quicker in starting their breakout.
''When you come back from road trips, and we had a successful road trip, we were a little bit flat coming through that first 10 (minutes),'' Stone said.
The Golden Knights got a power play when Kane was called for tripping a little more than eight minutes in. Eight seconds later, Pacioretty lasered a wrist shot past Dubnyk from his familiar spot atop the right circle.
''Thankfully, Flower was our best player in the first,'' DeBoer said about his 36-year-old goaltender. ''That first period, we could've been down by a couple and he allowed us to work into the game. The oldest player on the ice, to have that type of energy is impressive.''
Vegas looked like a different team in the second, skating quicker, creating scoring chances and peppering Dubnyk with 16 shots - the second-most for the Golden Knights in a period this season.
Overall shot attempts were dominated by Vegas 31-9, including scoring chances (17-6) and high-danger chances (7-3).
Meier cut the lead in half with a little more than five minutes left with his sixth of the season.
''You're going to have nights in this league where you're not going to feel great and you're going to have to grind out a win, and that's what we did tonight,'' DeBoer said.
Fleury earned his 20th win in March in 30 decisions with the Golden Knights.
SOLD OUT, SORT OF
As Clark County continues to open up more, and Nevada Gov. Steve Sisolak begins to allow larger gatherings, the Golden Knights had a ''capacity sold out'' crowd of 3,473 - 20% of a regular capacity crowd of 17,367.
San Jose's Patrick Marleau played in his 880th consecutive game, a streak that started on April 9, 2009. Marleau, who has played in 1,749 games and sits third on the career list, is on pace to break Gordie Howe's record of 1,767 games played back in Vegas, on April 19 against the Golden Knights. Mark Messier is second with 1,756 games played.
The teams play again Wednesday night.
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