Jonathan Quick notched 19 saves for the Kings, who trail the Blackhawks 2-1 in the best-of-seven series and will host Game 4 Thursday.
Justin Williams, Slava Voyonov and Dwight King scored for Los Angeles. The Kings outshot Chicago 28-20.
Quick faced only three shots in the second period but allowed a goal by Bryan Bickell on one of those shots that cut the Kings' lead to 2-1.
King made it 3-1 with an empty-net goal in the closing seconds of regulation.
Corey Crawford stopped 25 shots for the Blackhawks, who won the first two games of the series on their home ice.