Mathias Laborda scored the winner in a penalty shootout to give Vancouver victory over Los Angeles FC on Saturday and a berth in the semifinals of the Major League Soccer playoffs after the teams drew 2-2 after extra time.
Emmanuel Sabbi and Laborda scored first-half goals to put the Whitecaps 2-0 up at their domed B.C. Place stadium.
But LAFC hit back in the second half with two goals from South Korean star Son Heung-min, the dramatic equaliser coming in the fifth minute of stoppage time after Vancouver had just been reduced to 10 men.
Tristan Blackmon was issued a second yellow card, but the Whitecaps held out in extra time to take it to the shootout.
Son missed the first penalty, clanging his shot off the right post, and Sebastian Berhalter put Vancouver ahead.
When LAFC's Marco Delgado sent his penalty over the bar, Ryan Gauld converted to give the Whitecaps a 3-1 lead.
Andrew Moran kept LAFC's hopes alive before goalkeeper Hugo Lloris saved from Vancouver's Edier Ocampo.
Frankie Amaya again kept LAFC alive as he levelled the shootout, but Laborda sealed a 4-3 win with the final penalty.
SAN DIEGO OR MINNESOTA AWAIT
The Whitecaps advance to the Western Conference final for the first time, where they will face either top seed San Diego or fourth seed Minnesota United, who play on Monday.
The Eastern Conference semifinals will be played Sunday when Lionel Messi's Inter Miami visit Cincinnati and New York City go to top-seeded Philadelphia.
Both the Whitecaps and LAFC were boosted by mid-season arrivals of superstar talent with Germany's Thomas Muller, a former Bayern Munich midfielder, joining Vancouver and Son, a former Tottenham striker, joining LAFC.
In their first season under Danish coach Jesper Sorensen, the Whitecaps set a club-record points total, reached their first-ever CONCACAF Champions Cup final and challenged for the MLS Supporters' Shield.