As a result, Robbie Keane scored in the 47th minute to give the Los Angeles Galaxy a 1-0 victory over Vancouver, stretching the Whitecaps' losing streak at Stub Hub Center to five games.
Since joining Major League Soccer in 2011, Vancouver has not won a game on the road against L.A.
"In two seconds or five seconds, we lost the game," Vancouver midfielder Gershon Koffe said.
Despite the temporary loss of focus, however, Whitecaps coach Carl Robinson viewed his team's performance as a solid one.
"We showed that we were able to compete with the top teams away from home," Robinson said. "One minute of lack of concentration at the start of the second half cost us."
The Galaxy's Juninho began the scoring sequence with a long ball from midfield to Stefan Ishizaki on the right flank. With the Whitecaps' Jay DeMerit marking him, Ishizaki saw an unmarked Keane racing toward the goal.
Ishizaki sent the ball to Keane, who volleyed it with his left foot inside the left post from six yards.
Kekuta Manneh had two chances to give the Whitecaps an early lead but Galaxy goalkeeper Jaime Penedo foiled him both times.
In the 32nd minute, Manneh struck a 10-yard line drive that Penedo deflected while diving to his left. Then in the 45th minute, Penedo blocked Manneh's point-blank shot seven yards from the goal.
"He was electric in the first half," Robinson said about Manneh, who made his first start of the season.
"I think it would have been a different game (if Manneh had scored). I felt we were slightly on top in the first half."
Vancouver displayed a dynamic defence during that half despite missing midfielder Matias Laba, who was suspended after being ejected April 5 against Colorado. The Whitecaps hustled after disputed balls, intercepted passes and applied pressure throughout the field.
The Whitecaps had a chance to force a tie in the 77th minute, but Penedo leaped to grab Kenny Miller's 8-yard glancing header off Nicolas Mezquida's corner kick.
Penedo finished with four saves.