Nicolas Lodeiro scored on a pair of penalty kicks four minutes apart in the first half, and the Seattle Sounders were able to finish off a 3-0 victory over visiting Los Angeles FC on Friday.
Lodeiro scored in the 29th and 33rd minutes to give him four goals on the season.
Raul Ruidiaz added a left-footed goal in the 82nd minute, turning a string of tight passes into his eighth score of the season. Sounders goalkeeper Stefan Frei made two saves to earn his fourth shutout of the season.
The first Seattle shot from the penalty spot was awarded after a handball in the box charged to LAFC's Dejan Jakovic, while the second came on a foul in the box by Latif Blessing on Seattle's Yeimar Gomez.
Jakovic's handball was not called on the field but was radioed to referee Joseph Dickerson to confirm via replay.
It was the second consecutive victory for Seattle (6-2-3, 21 points), which moved into the top spot in the Western Conference ahead of idle Sporting Kansas City. The Sounders were coming off a 7-1 victory over the San Jose Earthquakes on Sept. 10, when they set an MLS record for the fastest five goals in a game (33 minutes).
The Sounders have now defeated LAFC twice since they were eliminated by their conference rivals during the knockout stage of the MLS is Back Tournament on July 27. LAFC was eliminated one game later by Orlando City FC in penalty kicks.
LAFC (4-5-3, 15 points) lost for the third time in their past four games. They have had MLS MVP Carlos Vela on the field for just 57 minutes since the second game of the season back in March. Vela opted out of the MLS is Back Tournament, then came away with a knee injury during the opening game of the second stage of the league's return to action.
The Sounders are now 4-1-1 since teams returned to play in MLS stadiums last month. LAFC are just 2-5-0 over that same stretch, and their overall record has dropped below the break-even mark for just the second time in their brief three-year history.