The blowout victory put an emphatic end to a club-record, eight-game winless streak for LAFC (7-9-6, 27 points). It also ended Sporting Kansas City's six-game unbeaten streak.
Fall connected on a header off a corner kick from teammate Eduard Atuesta in the 18th minute. Then after halftime, the game changed.
A foul committed by Sporting K.C.'s Roger Espinoza resulted in a red card after a video review, forcing the visitors to go with 10 men the rest of the way. And they could not stop LAFC.
With Espinoza angrily leaving the field, it seemed that with him went the spirit of his team. Fall scored again off a cross from Atuesta in the 61st minute to make it 2-0. Then Cristian "Chicho" Arango, denied moments before, scored on an tap-in the 71st minute.
After a Kansas City goal was disallowed due to an offside call, LAFC's Danny Musovski broke free for a one-on-one attempt against Sporting goalie Tim Melia, and Melia took Musovski down with an aggressive tackle that was resulted in a penalty kick.
Atuesta converted the spot kick in the 87th minute to complete the scoring.
LAFC's Latif Blessing was injured twice, once in each half. First he was inadvertently kicked in the side of the head by a teammate, and then his right knee collided with a Sporting Kansas City player, but he played on.