Vegas became the first Western Conference team to clinch when the Nashville Predators lost 2-0 at the Pittsburgh Penguins.
"It's obviously great to clinch a playoff spot," Golden Knights forward Nicolas Hague said. "We got our foot in the door there now. We've got some huge games coming up to try and solidify a [top seed]. We've got teams in the West and a couple big games against divisional teams to try to separate ourselves, and hopefully, we can kind of have a say in who we end up playing."
Ben Hutton had two assists, and Laurent Brossoit made 21 saves for Vegas (46-22-7), which is two points ahead of the Edmonton Oilers for first place in the Pacific Division, and three ahead of the Los Angeles Kings. Edmonton won 2-0 against Los Angeles on Thursday to move into second.
"Clinched a playoff spot, so checked that box off. Now we want to try to win the next thing, which was a game in front of us, and we looked out of sorts a lot of the night," Golden Knights coach Bruce Cassidy said. "They put some pressure on us. They were skating well. Reloading well. [It] was probably one of our poor nights executing."
Logan Couture scored on a breakaway 50 seconds into overtime, and Mario Ferraro had a goal and an assist for the Sharks (21-39-15). James Reimer made 23 saves.
"I thought for most of that game, we were the better team," said Couture, the San Jose captain. "We played extremely hard. We played smart. We played good hockey."