LOS ANGELES (AP) — Although Los Angeles FC had the best regular season in Major League Soccer history, the 2-year-old club had never been this deep in the playoffs.

The tough, tested Seattle Sounders go deep almost every year, and they'll get to play for another championship after a vintage display of postseason grit and guile in the Western Conference final.

Nicolás Lodeiro scored a goal and assisted on two more by Raúl Ruidíaz, and the Sounders advanced to the MLS Cup final for the third time in four years with a 3-1 victory over LAFC on Tuesday night.

Ruidíaz and Lodeiro scored four minutes apart in the first half to claim the lead for the Sounders, who held probable MLS MVP Carlos Vela to one shot on goal while they upset the Supporters' Shield winners with a superb big-game performance.

Los Angeles' MLS newcomers have a raucous stadium and a thrilling style of play, but the Sounders have years of playoff experience that LAFC can't match. Seattle's veterans pushed, shoved and carried them back to the one-game final, where the Sounders won the league title in 2016 and lost to Toronto FC in 2017.

"The many times that we've been to MLS Cup now has been off grit, has been off not playing pretty," midfielder Cristian Roldan said. "It's been off winning in different ways. Today we won in a different way. We locked down defense. We scored on our few opportunities. In other games, maybe we would play pretty. But we knew it was going to be a tough opponent away from home. We adjusted accordingly. Sometimes we would press. Sometimes we would sit back. Overall, it was just a fantastic performance."

Seattle slowed down the most potent offensive team in MLS history with physical defense, sometimes on the edge of legality. The Sounders committed 12 fouls and appeared to get away with two handballs in their box, but LAFC failed to capitalize on any of its meager chances after Eduard Atuesta scored on a free kick in the opening minutes.

Lodeiro joyously carried the conference trophy back to the visitors' locker room at Banc of California Stadium after an on-field celebration that was drowned out by LAFC fans' singing.

"We wanted to push LAFC into areas where they were less effective," Seattle coach Brian Schmetzer said. "That was the entire game plan, just to see if we could slow down their attack. And then on the attacking side, we knew we could create chances against this team. They take many risks when they defend or counter-press. Our guys were well coached. They did exactly what we needed to do to get into their half of the field."

Seattle will either host Toronto or visit defending champion Atlanta United for the MLS Cup final next Sunday, Nov. 10. The Eastern Conference finalists meet Wednesday night.

LAFC reached the MLS records for points, goals and goal differential during the long MLS regular season. LAFC then beat the crosstown LA Galaxy 5-3 last Thursday for its first playoff victory.

But Seattle largely kept the ball away from Vela, who followed up his record 34-goal regular season with two goals against the Galaxy last week. Diego Rossi also was barely a factor, managing just two shots.

"Nobody expected this end for our season," Vela said. "But we know in the playoffs, it's one game, and if they make better plays than you, you're out. In the end, I think we have to be proud with how we've done all year, and we have to learn. We have just two years as a club. We have things to improve."

Seattle beat LAFC for the first time in five meetings. The Sounders celebrated with the large section of visiting fans before climbing on a stage and raising the trophy despite loud songs from LAFC's indefatigable North End supporters' section.

Lodeiro followed up his outstanding performance against Real Salt Lake in the conference semifinal with another dominant offensive game. The 30-year-old Uruguayan set up Ruidíaz's goal and then scored his own in a blistering sequence late in the first half.

"We never stopped believing we could win," Schmetzer said. "We found a way to score the equalizer, and I think the second goal stunned LAFC a little bit. They were going, 'OK, what's going on here? This shouldn't happen.'"

Ruidíaz made it 3-1 in the 64th minute when Lodeiro stole an attempted clearance and fed him for a beautiful shot past Tyler Miller, the former Sounders backup goalkeeper. Ruidíaz, the 5-foot-7 Peruvian forward, has six goals in just five career MLS postseason games.

LAFC pushed in the second half but couldn't get through.

“If we play this game 10 times, we probably win nine out of 10,” LAFC midfielder Mark-Anthony Kaye said. “But playoffs are just different.”