Forwards Andre Burakovsky, Evgeny Kuznetsov and Jason Chimera scored for the Capitals (41-10-4), who have not lost consecutive games in regulation this season.
"I thought gradually, throughout the game, we got better, because we had to," Capitals forward Justin Williams said. "They got the better of the play. They were outshooting us, outplaying us, outbattling us. Slowly, in the third period, we started to take things over, and things started to move a bit in our direction. You know, we said it on the bench: We were getting stronger and they were fading a bit."
Forward Anze Kopitar scored a shorthanded goal, and Jonathan Quick made 29 saves for the Kings in his return from a lower-body injury that caused him to miss three games. Los Angeles (33-20-3) is 2-3-0 on its seven-game road trip.
"The goalies made some big saves," Kings coach Darryl Sutter said. "We couldn't get that second one. But we had lots of good opportunities. The last five minutes you were just trusting the guys that you have on the ice, and we probably got caught with some inexperience on the back end on that last goal."