Andre Lee scored his first NHL goal for the Kings (22-10-5), who have won eight straight at home. Quinton Byfield and Adrian Kempe also scored, and Mikey Anderson had two assists.
"He couldn't wipe the smile off his face," Kings coach Jim Hiller said of Lee.
Los Angeles has won three straight coming out of the Christmas break and is 11-2-2 in its last 15 games.
Jake Allen made 21 saves for the Devils (24-14-3), who have lost three straight in regulation for the first time this season.
New Jersey was coming off a 3-2 loss at the Anaheim Ducks on Tuesday.
"It was obviously a good bounce-back game from what we had yesterday, but we've obviously got to find a way to score," New Jersey forward Stefan Noesen said.
The Kings took a 1-0 lead at 6:23 of the second period.
Los Angeles defenseman Jordan Spence lofted a pass from his own end that bounced near the New Jersey blue line. Lee was a stride ahead of Devils defenseman Brett Pesce and held him off before banking the puck off the bottom of the crossbar for his first goal in his 19th NHL game.
"It was a dream," Lee said. "Good pass from (Spence) there, flipped it up in the air, and just got it past him and put it in the back of the net. But, yeah, great feeling."