Jack Eichel and Nic Dowd scored for the Golden Knights, who are the No. 1 seed from the Pacific Division. Carter Hart made eight saves.
Utah has won two in a row to lead the best-of-7 series 2-1. Game 4 will be here on Monday (TBD; Utah16, SCRIPPS, ESPN).
“I thought we took a step forward in how we have to play from Game 2 (a 3-2 loss on Tuesday),” Vegas coach John Tortorella said. “Game 2 we gave up 27 to 28 scoring chances, and that certainly didn't happen tonight. You know it's a series of ebbs and flows, but I did like a lot of our minutes tonight.”
Weegar gave the Mammoth a 1-0 lead at 12:59 of the first period. Kailer Yamamoto couldn't connect on a pass with Liam O'Brien in the left circle, but Weegar skated into the loose puck in the high slot and scored with a slap shot that hit the mask of Hart before going in under his blocker arm.
“There's lots of depth here,” Weegar said. “Obviously, some guys are eventually going to step up, too, so that's also a good sign. But I've talked about it a lot with this team. There are four lines that have identities, that can score, play both sides of the puck, and (six defensemen) the same way.”
Guenther made it 2-0 with a power-play goal at 17:45, roofing a one-timer under the crossbar from the top of the left circle.
“No one is stopping Guenther's shot,” Tortorella said. “That's just a bomb.”
Crouse pushed the lead to 3-0 at 4:06 of the second period, redirecting Nick Schmaltz's centering pass on a rush over the blocker of Hart.
Crouse then scored his second goal of the period at 9:48, beating Hart blocker side again with a wrist shot from the high slot to make it 4-0.
“I think the biggest thing that we can take away from these games is there's going to be waves on both sides,” Crouse said. “We're going to have our pushes, they're going to have their pushes. It's just whoever can stick with it, and Vegas is playing really good hockey. ... I think just our mindset leading into each game, it's just been simple. We just got to keep going, take it one shift, one game at a time and see what happens.”