The Seattle Sounders pulled off a huge 3-1 upset of LAFC with a pair of goals from Raul Ruidiaz to eliminate the Supporters' Shield winners from the MLS playoffs on Tuesday night at Banc of California Stadium.

The win gives the 2016 MLS Cup-winning Sounders a spot in the 2019 final (Nov. 10 at 3 p.m. ET on ABC) against the winner of Wednesday's Eastern Conference final between Atlanta United and Toronto FC.

It was a difficult defeat for LAFC, which set an MLS record with 72 points during a 21-4-9 regular season. The team's star man Carlos Vela, who scored a league-record 34 goals in the regular season and added two more in a 5-3 playoff victory against the rival Los Angeles Galaxy last week, was kept largely in check throughout the match.

The home team opened the scoring in the Western Conference final just after the 15-minute mark when Eduard Atuesta buried a free kick from 20 yards out past Stefan Frei.

The Sounders, who had never beaten LAFC in four previous tries, struck back in rapid succession to pull into the lead in the next 10 minutes from a superb Ruidíaz turn and finish followed by a well-taken shot from distance from Nicolas Lodeiro to make the score 2-1 in favor of the visitors.

LAFC midfielder Latif Blessing went down with an injury right before halftime and was replaced by Mark-Anthony Kaye, who was returning from an injury of his own that he picked up on international duty with Canada, as Seattle took its lead into the break.

Bob Bradley went to the bench again early in the second half to replace Brian Rodriguez with Adama Diomande, who had been decisive in LAFC's semifinal win over the LA Galaxy, and the hosts looked more dangerous after the substitution.

But it was Seattle that would strike again through Ruidiaz, who popped up against the run of play, took a pass from Lodeiro and blasted his second touch past Tyler Miller to give the Sounders a two-goal lead.

The goals were Ruidiaz's fifth and sixth in the playoffs since joining the Sounders, the most by any player in the postseason in that span.

The hosts pushed hard to find a way back in, but it was all in vain as Seattle saw out the result to book a spot in the MLS Cup final, the Sounders' third in four years, on Nov. 10.