SANDY, Utah -- Playing the underdog was an familiar role for Real Salt Lake on Thursday.

RSL reached the U.S. Open Cup final and was in the thick of the Supporters' Shield race for Major League Soccer's best regular-season record throughout the year.

Facing a 1-0 deficit against the Los Angeles Galaxy after the first leg of the teams' Western Conference semifinal series, the underdog role was suddenly thrust on Salt Lake. RSL embraced the role with enthusiasm and played like a favorite.

Sebastian Velasquez scored his first career MLS goal before halftime, and Chris Schuler added the game-winner in the first half of overtime to lift Salt Lake to a 2-0 victory over Los Angeles on Thursday night.

RSL advances to the Western Conference finals after winning the series 2-1 on aggregate. Salt Lake, in the conference finals for the third time in five years, will host the Portland Timbers in the first leg Sunday night.

"I thought the guys, again, brought energy on both sides of the ball," RSL coach Jason Kreis said. "We had a commitment that was spectacular. There were players that were wanting to go forward, to take opportunities and to take risks. The amount of work they put in defensively was absolutely spectacular -- especially in the midfield."

The result ended the Galaxy's bid for a third consecutive MLS Cup. For the second time in five years, Salt Lake eliminated Los Angeles from the playoffs.

Salt Lake improved to 2-2-2 all time in second-leg matches in playoff series. RSL's previous second-leg triumph came against the Columbus Crew in the 2009 Eastern Conference semifinals -- en route to winning the team's lone MLS Cup.

After a shaky offensive performance in the first leg in Los Angeles, RSL turned in a better effort at home in the first half Thursday. Salt Lake strung together several nice passes, mixed in good ball movement and dominated possession. The Galaxy made it easier for Salt Lake to create scoring chances with poor clearances and by turning the ball over in the midfield.

"Eleven players defended," RSL goalkeeper Nick Rimando said. "That's the big key. The way we play in our system, we need everybody to pitch in and defend and give the effort. Tonight, we did that."

Salt Lake tied it at 1-1 on aggregate in the 35th minute with Velasquez's header. Chris Wingert sent a cross deep into the box to an unmarked Velasquez, who slipped a header past Galaxy goalkeeper Jaime Penedo.

"They played better than we did," Galaxy coach Bruce Arena said. "They were very direct. They just played the ball behind us and put our backs under pressure and scrapped a lot."

RSL had several chances to go ahead in the second half, but unlucky bounces kept them from notching a potential game-winner.

RSL midfielder Javier Morales sent a cross in to Schuler off a corner kick in the 74th minute. Schuler headed the ball into the crossbar. Then Salt Lake's Alvaro Saborio collected the ball outside the box in the 78th minute and blasted it from distance. The ball failed to curl enough and struck the bottom of the left post.

The costliest near-miss occurred in the 84th minute. Morales lined up for a free kick and hooked a through ball over the defensive wall and into the net. However, the apparent goal was waved off after an RSL foul in the box.

Schuler helped Salt Lake bounce back in overtime. He collected a cross from Morales on a free kick in the 102nd minute. Schuler took the ball at the back post and threaded it just inside the post for the go-ahead goal.

"Robbie (Keane) and I couldn't pull a rabbit out of a hat tonight, so we needed some other guys to step up and make plays," Los Angeles forward Landon Donovan said. "Unfortunately, it didn't happen, so it made it difficult for everyone."

NOTES: RSL midfielder Ned Grabavoy was absent from the starting lineup because of a left hamstring strain he suffered in Sunday's first leg against the Galaxy. Sebastian Velasquez started in his place. ... The teams met in the playoffs for the fourth time. Real's lone victory in the previous three meetings came in the 2009 MLS Cup title match. ... RSL and Los Angeles are the only MLS teams in the league's post-shootout era to reach the 15-win and 50-point plateau over four consecutive seasons. ... Salt Lake was 2-1-1 at Rio Tinto Stadium during the regular season following a road loss.