Jack Johnson added a goal and two assists for the Kings, who completed the second game of a 10-game road trip. Los Angeles improved to 4-0-1 in its last five outings.
Magnus Paajarvi scored for the Oilers (15-27-8), who have lost two straight and 16 of 19. Goalie Nikolai Khabibulin has dropped his last 12 starts.
Edmonton coach Tom Renney was behind the bench despite the death of his father on Tuesday.
The Oilers controlled the bulk of the play for most of the scoreless first period, outshooting the Kings 12-5, but it was the Kings who had the best chance with five minutes left.
Anze Kopitar had Khabibulin down, but hit defender Tom Gilbert with a shot before the net was knocked off the moorings.
Edmonton came close a couple times on the power play late in the first but Kurtis Foster's slap shot hit the post. A loose puck that had fallen behind goalie Jonathan Quick was then cleared to safety before Linus Omark could get to it.
The Oilers opened the scoring three minutes into the second period as Sam Gagner made a beautiful move to spin past Los Angeles's Trevor Lewis and found Paajarvi at the side of the net for the goal.
Los Angeles countered 24 seconds later on the power play as Smyth tipped Drew Doughty's shot past Khabibulin for his 20th goal. The Kings went ahead 2-1 midway through the second on another power play as Smyth again deflected Doughty's point shot.
Los Angeles had a chance to go ahead by two goals four minutes into the third when Jarret Stoll was awarded a penalty shot after being hauled down by Ladislav Smid. Stoll was unable to slip the puck between Khabibulin's pads.
The Kings went ahead 3-1 with five minutes remaining when Johnson's shot from the point found its way into the net.
Notes: The Kings won the two previous meetings against the Oilers in Los Angeles. ... The Kings are 7-0-4 against the Oilers since losing 5-4 on Feb. 28, 2008. ... Oilers forward Ales Hemsky returned after missing four games and All-Star weekend because of a concussion. Edmonton sent RW Zack Stortini to Oklahoma City (AHL) after he cleared waivers. ... Oilers rookie RW Jordan Eberle is expected to return to the lineup on Friday. Eberle has been out since Jan. 1 with a sprained ankle. ... Los Angeles was without LW Scott Parse (hip). LW Marco Sturm (knee) is day-to-day. ... The Kings are on the long road trip became their home arena will host the Grammy Awards and the NBA All-Star game.