Dominik Kahun scored on the second shift of his debut to put the Sabres on the board 2:16 into the contest. Their second goal wouldn't come until Jeff Skinner buried a backhand shot with 11.8 seconds remaining, at which point Vegas had already padded its lead with an empty-net goal from Smith.
What transpired in between was a tightly contested game between a Sabres team working desperately to make up ground in the standings and a Golden Knights squad that entered the night having won seven straight games, including a shutout of Edmonton two nights prior.
Nicholas Roy scored for Vegas to tie the game at one goal apiece in the first period, giving way to an evenly played second. The website Natural Stat Trick had both teams generating six scoring chances and two high-danger attempts at 5-on-5 in the middle period.
"I thought on both sides of the puck we played a really strong game here today and just had a lapse to give them the lead in the third where it was an even game," Sabres coach Ralph Krueger said. "You're waiting for a breakdown and we gave it to them. It's a defensive lapse."
Karlsson found a lane into the blue paint to break the tie just 3:06 into the final period. The play began with a perfectly placed pass from Chandler Stephenson at the point to Max Pacioretty in the slot. Pacioretty shot wide, chased the puck behind the net, and then wrapped around to the front and found Karlsson driving into the crease.
Smith doubled the lead with a wrap-around goal less than three minutes later.
"For the most part, I thought we managed our game pretty well," McCabe said. "I thought we were really good through the neutral zone especially. But yeah, in games like this, they're so tight that every single shift matters, every single battle matters, and unfortunately they won a couple more of those battles and found the back of our net."