Anze Kopitar and Trevor Moore each had a goal and an assist, and Cal Petersen made 19 saves for the Kings (12-10-6), who had lost two straight and are 5-1-1 against St. Louis this season. Jaret Anderson-Dolan had two assists in his return after missing the previous 12 games with an upper-body injury.
"I think that we respect them enough, we really rise to the occasion," Kings coach Todd McLellan said. "We have checked well against this team. Our special teams seem to get us one more than they get a night, and we've got outstanding goaltending in all of the matches we've played against them."
Los Angeles is three points behind St. Louis for fourth place in the Honda West Division with one game in hand.
"The most important thing right now is we're in the mix," McLellan said. "We're there. We're swinging with the big boys. We've earned the right to be respected around the League."
Mike Hoffman scored, and Jordan Binnington made 20 saves for the Blues (14-10-5), who are 0-2-3 in their past five games.
"There's no tricks or magic that's going to get you out of this hole," St. Louis coach Craig Berube said. "You just got to come together as a hockey team on the ice and got to be able to work together out there and do it together. And that's the key."
Drew Doughty gave the Kings a 1-0 lead with a power-play goal at 3:21 of the first period. It was Doughty's 64th career goal on the man-advantage, passing Wayne Gretzky for ninth in Los Angeles history.
"A couple of good shifts led to that drawn penalty, and then our power play has been good all year (10th in NHL at 25.7 percent), and we cashed in," Moore said.
Carl Grundstrom tucked a shot around Binnington's right pad 58 seconds later to make it 2-0, and Moore extended the lead to 3-0 at 14:11 when Sean Walker's centering pass redirected in off his skate.
"It was just good forechecking work by all three of us, and then when you get them a little tired out there, you're able to capitalize on that," Moore said.
