LAFC (12-12-9, 45 points) dominated with 11 shots on target to two for the Whitecaps. However, Vancouver (12-9-12, 48 points) ended the night still in playoff position in the Western Conference.
The Whitecaps hold sixth place while LAFC is in ninth, two points out of the seventh and final spot with one game to play.
That means LAFC needs to win at Colorado on the regular season's last day, Sunday, to make the postseason, plus perhaps get some help. Vancouver would make the playoffs with a draw or a win over visiting Seattle on Sunday.
Cristian Dajome put the Whitecaps in front 1-0 in the 14th minute. He gathered in a cross from Brian White, made a move with the ball to clear space and finished from in front for his 10th goal of the season. For the moment, Vancouver had a playoff spot clinched.
LAFC spent lots of time in the Vancouver end but repeatedly was turned away by goalkeeper Maxime Crepeau and the Whitecaps' defense. Crepeau had five saves in each half.
Finally, as first-half extra time neared its end, LAFC defender Mamadou Fall tapped in a deflection.
The play was first whistled for offside but was reviewed on video. Officials overturned the call into a goal, and despite protests from the Whitecaps, the teams went into halftime tied at 1.
The second half saw LAFC go to the bench for midfielder Jose Cifuentes and forward Carlos Vela, two of the club's top players. Vancouver also turned to offensive subs in Deiber Caicedo and Lucas Cavalllini, but despite opportunities, neither team could produce a go-ahead goal.
In the third minute of second-half stoppage time, Los Angeles' Cristian Arango came just short of getting his head on a cross directly in front of the goal.