Fischer also had an assist for his second NHL career multipoint game.
Kuemper made 30 saves for Los Angeles (12-8-3), which lost its third straight game and seventh in its past eight (1-6-1).
"At the end of the day we've got to win a hockey game, so let's not pat ourselves on the back and say we played better," Kings coach John Stevens said. "I think the guys played hard. I think the guys are totally invested. If it was a compete issue I'd be really concerned, but there's execution in certain parts of our game that clearly have to be a lot better."
Scott Wedgewood made 23 saves for Arizona (6-16-3). Wedgewood relieved injured starter Antti Raanta on Wednesday, which he believed helped him prepare for Friday.
"Any time you have an opportunity to know a day in advance as a goaltender, there's no unknowns," Wedgewood said. "Getting a start and getting through the first period, we played well and we're up one. It just kept flowing from there."