Tanner Pearson had a goal and an assist, and Brett Howden and Victor Olofsson also scored for Vegas (25-8-3), which is 10-1-0 in December.
“Both teams were sloppy at times executing a good first pass. Is that the forecheck pressure? Probably a little bit of both, right? Who knows, maybe the ice was off or the pucks were bouncing,” Golden Knights coach Bruce Cassidy said. “We're a lot closer (to where we want to be defensively) than we were six weeks ago, and it's one of the reasons we've had a terrific month."
Dan Vladar made 34 saves for Calgary (17-12-7), which had won two straight and had its five-game point streak end (3-0-2).
“[Vladar] was our best player today. He made some saves and he gave us a chance to win,” Flames coach Ryan Huska said. “He showed some real compete early on to give that group the boost that you would hope they need.
“It was a hard game. Now you turn the page and get ready for another hard game against Vancouver (on Tuesday)."