Vegas, which entered the day in third in the Pacific Division, fell one point behind the Los Angeles Kings, who won 5-4 in overtime against the Chicago Blackhawks on Thursday.
Frank Vatrano got his third hat trick of the season, and Cutter Gauthier had an assist in his NHL debut for Anaheim (27-50-5). Lukas Dostal made 29 saves.
Jack Eichel scored, and Adin Hill made 19 saves for Vegas (45-29-8), which had won three straight.
Vatrano gave the Ducks a 1-0 lead at 4:25 of the second, scoring a power-play goal with a one-timer glove side from the top of the right circle.
Eichel tied it 1-1 at 18:47 with his own power-play goal. His centering pass for Jonathan Marchessault deflected in off the stick of Ducks forward Isac Lundestrom.
Jackson LaCombe scored 51 seconds into the third period to put the Ducks back in front 2-1. Gauthier, who was selected with the No. 5 pick in the 2022 NHL Draft and was acquired in a trade with the Philadelphia Flyers on Jan. 8, had the primary assist on the play.
Vatrano scored 29 seconds later with a wrist shot from the top of the left circle on a rush to make it 3-1. He then completed the hat trick with a short-handed goal into an empty net to make it 4-1 at 19:43.
