The Kings have won back-to-back games to get to 40 points and enhance their playoff chances.
Los Angeles took a 2-1 lead into the third period, but Vladimir Tarasenko scored his second goal of the contest for the Blues 6:44 into the frame.
Mike Richards snapped the 2-2 tie with a wrist shot and Justin Williams added an empty-net goal with 1:16 to go.
Jonathan Quick made 20 saves for the Kings, who handed the Blues their third straight loss.
Jaroslav Halak surrendered three goals on 39 shots.
Man behind Doritos Locos Tacos passed away on Thanksgiving
Kate Moss Playboy shoot is classic Playboy, classic Kate