Sean Walker scored for Los Angeles (4-8-0), which has lost three games in a row and six of eight.
"I don't know what the reason is," Kings captain Anze Kopitar said. "It's a combination of everything. Sometimes, a little bit of fatigue, sometimes it's just flat-out sloppiness, sometimes it's just flat-out stupidity. Sometimes, it's just being caught in between the old system and the new system (under first-year coach Todd McLellan). That combines into a lot of goals-against that we can't give up in order to win games."
Strome gave the Blackhawks a 1-0 lead at 2:33 of the first period, scoring from the slot off a pass from DeBrincat.
David Kampf made it 2-0 at 2:26 of the second. Alexander Nylander crashed the net and made a no-look, backhand pass while falling to Kampf, who scored his first goal of the season from in front of the crease.
Strome made it 3-0 at 15:55, scoring again from the slot off a backhand pass from DeBrincat.
"It's a little bit of a reset I think," DeBrincat said. "We know what we can do together, so trying to play some good, smart hockey and the bounces went our way today."
DeBrincat made it 4-0 at 19:02, shooting the puck between goalie Jack Campbell's pads from the slot off a pass by Strome from below the goal line.
"It wasn't going in there for a while, and we got bounces today, so if we keep doing that then we're going to keep scoring goals and keep winning games," DeBrincat said.
Walker made it 4-1 at 3:35 of the third period, scoring from the top of the right face-off circle off an Alex Iafallo pass off the boards.
Drake Caggiula gave Chicago a 5-1 lead with 2:07 remaining when the puck bounced off his skate and past Campbell.
Kings forward Nikolai Prokhorkin had three shots on goal and four hits in 14:28 in his NHL debut.
Campbell made 21 saves.