It was Carlson's 13th multipoint game this season for the Capitals (21-4-5). Ilya Samsonov made 22 saves.
Carlson has 42 points (11 goals, 31 assists), tied with Denis Potvin (1975-76) and Al MacInnis (1990-91) for second most in NHL history by a defenseman through 30 games. Bobby Orr had five seasons with at least 42 points through 30 games, including 56 in 1974-75.
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"I don't know what to say right now," Capitals forward Alex Ovechkin said. "He's the hottest guy out there. You can see, two highlight-reel goals again, and he's good."
Blake Lizotte scored, and Jonathan Quick made 19 saves for the Kings (11-16-2), who are 1-3-0 in their past four.
Carlson became the fifth Capitals defenseman to score 100 goals and the 13th U.S.-born defenseman to do so by giving the Capitals a 1-0 lead at 4:36 of the first period, scoring on a wrist shot from the right point.
Carlson also became the sixth Capitals player and first defenseman with 10 goals this season.
"Yeah, it's been fun to watch, certainly," Capitals coach Todd Reirden said. "The guys, you know, like to give him a hard time about it, and lots of things have gone his way. That being said, he's earned it, he's worked for it, he deserves it. It's not just the offensive stuff. He's blocking shots, playing rushes early. He's doing it all, obviously."