Vegas outshot New York 20-4 in the second period, including holding the Islanders without a shot for 17:13 spanning the second and third period.
"I didn't mind our first and third. Our second period, I thought, we lost too many battles," Trotz said. "We needed more chances, but you're not going to get any chances when you spend the whole second period in our end."
The Golden Knights continued to pressure the Islanders in the third period, outshooting them 15-9.
"It seems like since Day One here in Vegas, we never really got too uptight when we're up a goal," Smith said. "I think we just showed that again tonight. A lot of poise when we got pucks in our own zone."