Ryan O'Reilly started Los Angeles' comeback from two goals down at 8:11 of the second period. Landeskog tied at 2-2 with 7:02 remaining in the period, beating Mathieu Garon on the first shot he faced after replacing Ben Scrivens. Landeskog got the tiebreaker with 3:54 remaining, knocking in a rebound from just in front of the goal.
Jean-Sebastien Giguere made 23 saves for the Avalanche (3-3-0).
Mike Richards scored twice for Los Angeles, putting the Kings (3-3-1) on the scoreboard with 3:22 left in the first and doubling the lead 14 seconds into the second period. Scrivens had 17 saves and Garon finished with nine.
With 15 seconds left in the game, the Kings' Azne Kopitar had one final chance to tie with a loose puck just right of the net, but couldn't get a good shot off.
Andre Benoit had two assists for Colorado.
Kings captain Dustin Brown returned from a hamstring injury. Brown, who did not start, made his first appearance less than two minutes into the game. He had 18 goals and 11 assists last season.