White took a pass from Ryan Raposo and scored for an eighth time this season to give the Whitecaps (8-7-7) the lead for good.
Gauld notched his sixth and seventh goals of the season — scoring unassisted in the 10th minute and via a penalty kick in the 23rd to put Vancouver up 3-0 at halftime.
Gastón Brugman used an assist from Riqui Puig in the 61st minute to get the Galaxy on the scoreboard with his second goal of the season. Mark Delgado took a pass from Preston Judd in the 74th minute and scored his second of the season to pull the Galaxy within 3-2.
Sergio Córdova added his second goal this season, finding the net in the fourth minute of stoppage time to complete the scoring.
Vancouver improves to 3-1-2 in the last six meetings between the teams.
The Galaxy’s seven-match unbeaten run (3-0-4) ended.
When the league resumes play on Aug. 20, the Galaxy will host Real Salt Lake. Vancouver will host the San Jose Earthquakes.