Bouanga, on the left side, ran onto a ball played by Eduard Atuesta and drilled a line-drive cross to Olivera for a one-touch finish to give LAFC a 1-0 lead in the 18th minute.
Bouanga again found Olivera to make it 2-0 in the 36th. Atuesta’s through ball led Bouanga down the left side before he beat two defenders as he worked to the goal line and then played an entry to Olivera for a volley from point-blank range.
Vancouver (5-3-3) had its three-game unbeaten streak ended and lost for just the second time in its last seven matches.
Hugo Lloris had four saves for LAFC and recorded his third shutout of the season. The 37-year-old, who captained France to a World Cup title in 2018 and was a longtime club captain and icon at Tottenham Hotspur, had conceded 13 goals across six starts since his last clean sheet on March 23, a 5-0 win over Nashville.
Mateusz Bogusz tapped in a volley from six yards out off a perfectly placed cross by Bouanga to make it 3-0 in the 57th minute. The 22-year-old, who scored three goals as a rookie in 2023, has four goals this season.
Yohei Takaoka conceded multiple goals in a game for the first time since a 3-1 loss to the Galaxy on April 13, with two shutouts in that three-game span. Takaoka finished with five saves on Saturday.
LAFC (5-4-3) had conceded multiple goals in four straight matches but has just one loss — a 3-1 road defeat at the hands of the San Jose Earthquakes last time out — during that span.