Trevor Zegras scored, and Lukas Dostal made 25 saves for the Ducks (26-50-5), who have lost four of five.
“They’ve got good, high-end players that can score if you give them chances,” Anaheim forward Troy Terry said. “You don't want to give up power plays, and I think that's kind of the difference tonight.”
Dubois gave the Kings a 1-0 lead at 2:45 of the second period on the power play, scoring near the right post.
With Kopitar out, Dubois worked with the first power play in a position which was more familiar to him.
“I’ve never really played on the half-wall in my career, so to get back netfront is more what I’ve done basically my entire life,” Dubois said. “There’s an area of comfort, I think. To get back to what you’ve done for the past nine years of your life, it feels good.”
Rittich made a pad save on Frank Vatrano’s short-handed breakaway at 8:57 of the second to preserve the lead.
Rittich, who took over as starter Cam Talbot’s backup after Pheonix Copley tore his ACL in practice on Dec. 17, improved to 13-6-3.
“He just comes in and plays well,” Hiller said. “So that’s a really, really strong attribute by a goaltender that you don’t have to be in rhythm to be able to play well. So, give him credit, he made some saves tonight and was probably the difference in the game.”