Carlos Vela continued his prolific campaign for LA, scoring in a 3-0 win over Columbus Crew in Ohio.
Mark-Anthony Kaye opened the scoring before half-time, neatly tucking away a lovely pass from Latif Blessing.
LAFC left it late to seal its win, Adama Diomande scoring before a brilliant 20-yard strike from Vela made it 3-0.
Vela is up to 12 goals in as many games this MLS season, while LAFC moved five points clear at the top.
LA Galaxy is still second despite a third straight loss, going down to New York City 2-0.
Seattle Sounders joined them on 22 points after overcoming Houston Dynamo 1-0.
In the Eastern Conference, Philadelphia Union went three points clear at the top courtesy of a 2-1 victory over Toronto FC.
Chris Mavinga's unfortunate own goal gave Philadelphia the lead at BMO Field, only for Alejandro Pozuelo's 20-yard free-kick to bring Toronto level.
But Union found a 68th-minute winner through Jamiro Monteiro, who put away a pass from Kacper Przybylko.
Elsewhere, FC Cincinnati upset Montreal Impact 2-1 and Chicago Fire overcame Minnesota United 2-0.
Colorado Rapids remains winless after going down to Real Salt Lake 3-2, New England Revolution beat the San Jose Earthquakes 3-1 and New York Red Bulls recorded a 3-1 win over FC Dallas.