Petersen made the save on all 15 shots he faced over the final two periods, including a pad stop against Nico Hischier on a snap shot from the left face-off circle at 13:34 of the third period.
"We got to look back at the three losses we came in with, particularly how we lost them and the mistakes we're making," McLellan said. "We corrected a lot of those tonight. So that was a good first step."
Los Angeles will play at the New York Rangers on Monday (7 p.m. ET; MSG+, BSW, ESPN+, NHL LIVE).
"It's good getting the first one, especially with a back-to-back situation going to the Rangers," McLellan said. "It doesn't make the job any easier, but at least you have one in the bank."
NOTES:Kings forward Adrian Kempe played 17:55 and had five shots on goal after missing the past three games in NHL COVID-19 protocol. ... Bratt had the third two-goal game of his NHL career and first since Oct. 30, 2019, against the Tampa Bay Lightning. The Devils forward has seven points (four goals, three assists) during a five-game point streak. … Arvidsson has 11 points (four goals, seven assists) in his past 10 games. … Grundstrom's goal was his first since Nov. 27, ending a 14-game drought. … Petersen won his ninth game in 16 starts, tying his NHL career-high in wins set last season in 35 games.