LAS VEGAS -- William Karlsson scored the first hat trick in Vegas Golden Knights history, and they won their seventh game in a row, defeating the Toronto Maple Leafs 6-3 at T-Mobile Arena on Sunday.
Karlsson leads Vegas with 20 goals in their inaugural season. Pierre-Edouard Bellemare, Erik Haula and Jonathan Marchessault scored for the Golden Knights (26-9-2), who led 3-0 in the first period.
"Change in environment can be good for a player," said Karlsson, who scored 15 goals combined the past two seasons with the Columbus Blue Jackets. "I've gotten a lot of chances here in Vegas. I think I've done pretty well; I have two good linemates [Reilly Smith and Marchessault] I play with every night. They make it easy on me."
[WATCH: All Maple Leafs vs. Golden Knights highlights]
Auston Matthews scored two goals and reached 100 points in his NHL career, and Patrick Marleau scored for Toronto (23-15-2), which has lost two in a row.
Video: TOR@VGK: Matthews reaches milestone with second goal
"To come in their first year and do as well as they are, it's a testament to management and coaching and the players over there," Marleau said. "Those guys [have] got something to prove and they're doing a good job and it's a good team over there."
After not scoring in seven of eight games from Dec. 3-19, Karlsson has scored in three of the past four. This was his fourth multigoal game of the season.
"I just know when the passes are coming and when they're not," Karlsson said. "More often than not, they're going to pass it to me."
Vegas went 11-1-1 in December, losing in regulation Dec. 1. Its seven-game winning streak and 12-game point streak are the longest by an NHL team in its inaugural season, according to the Elias Sports Bureau. The 11 wins in December are the most by a team in its first season.
Video: TOR@VGK: Karlsson buries Smith's feed on the rush
Malcolm Subban made 20 saves for his 10th win (10-2-0).
"I don't even know what's happening right now. We're just finding ways to win every night," Marchessault said. "It's been honestly one of my most favorite years, for sure. It's so fun playing hockey right now. We don't overwork, we just do the right thing."
The Golden Knights scored three times in the first 13:24. Bellemare scored at 2:24; Karlsson followed at 4:17; and Haula's goal gave Vegas a 3-0 lead.
Karlsson's second goal came at 8:26 of the second period for a 4-1 lead, and he scored into an empty net with 1:36 left in the third.
"I thought [Vegas was] a real quick team," Toronto coach Mike Babcock said. "I thought they played well. In the end, we're going home and need to regroup."
Marleau scored at 5:07 of the second period to make it 3-1. Matthews scored at 19:12 of the second and 27 seconds into the third period to make it 4-3. Marchessault made it 5-3 at 6:11 with an assist from Karlsson.
Video: TOR@VGK: Marleau slides puck in off Subban
Goal of the game
Karlsson's goal at 18:24 of the third period.
Video: TOR@VGK: Karlsson completes Vegas' first hat trick
Saves of the game
Subban's three saves starting at 15:20 of the second period.
Video: TOR@VGK: Subban turns in three strong saves
Highlight of the game
Karlsson's goal at 8:26 of the second period.
Video: TOR@VGK: Karlsson nets his second on fortuitous hop
They said it
"I thought the crowd was good. The energy was good. I thought the whole thing was good. I would have liked us to been better initially. You have to give them credit." -- Maple Leafs coach Mike Babcock
"Honestly, we're not worried about playoffs. The playoffs will worry about themselves in April. We're worried about one game at a time." -- Golden Knights coach Gerard Gallant
Need to know
Matthews has 57 goals and 43 assists in 112 NHL games. … Haula's goal in the first period was his seventh in December, 14th of the season, and his 26th point of the season, equaling his total of last season with the Minnesota Wild. … The Golden Knights have not scored on their past 12 power-play opportunities. … Maple Leafs forward Nazem Kadri was scratched with an upper-body injury he sustained Thursday.
Maple Leafs: Host the Tampa Bay Lightning on Tuesday (7 p.m. ET; TVA Sports, SNO, SUN, NHL.TV)
Golden Knights: Host the Nashville Predators on Tuesday (7 p.m. ET; ATTSN-RM, FS-TN, NHL.TV)
Video: Karlsson earns hat trick in Golden Knights' 6-3 win