Hunt scored his first goal of the season with a slap shot from the top of the left face-off circle to make it 3-2 at 9:47, and Neal finished a 2-on-1 at 12:15 for a 4-2 lead.
"I just don't think we were competitive enough," Tortorella said. "I thought we had some good minutes along the way, but overall we just lost too many battles on the puck. The second period, obviously, it just got away from us."
Karlsson scored his second of the night at 9:21 of the third to make it 5-2. Defenseman Shea Theodore lifted the puck from the Vegas zone to Karlsson at the Columbus blue line. It landed right on Karlsson's stick blade, and he deked forehand to backhand for his Golden Knights-leading 27th goal.
"It was right on the tape," said Karlsson, who was selected from Columbus by Vegas in the NHL Expansion Draft. "It's been a while since I've seen a pass like that. I'm glad I finished it off like that in style. [Theodore's] a very talented player and it shows what he can do."
Calvert scored at 12:53 of the third period to make it 5-3.
Erik Haula made it 6-3 with an empty-net goal with 1:02 remaining.