PORTLAND, Ore. - Nat Borchers teased Liam Ridgewell about his first goal of the year after the Portland Timbers beat FC Dallas 3-1 in the first leg of Major League Soccer's Western Conference finals.

"It's about time," Borchers said, chiding his backline teammate about the breakthrough goal in the first half that put Portland in front.

Borchers and Dairon Asprilla also scored in the victory Sunday night that gives the surging Timbers the upper hand going into the second leg, set for Toyota Stadium in Texas next Sunday. The winner on aggregate will advance to the MLS Cup final Dec. 6.

Portland is unbeaten at 5-0-2 in its last seven matches, including a 2-0 victory over the Vancouver Whitecaps to win the conference semifinal. Dallas advanced following a 4-2 penalty shootout in the second leg of its semifinal against the Seattle Sounders.

"We didn't want to put ourselves in this spot," Dallas coach Oscar Pareja said. "But we've done it before, and I believe in this group."

The Timbers were without key contributors Diego Valeri and Rodney Wallace because of yellow card accumulation, but they'll be available for the second leg.

"To lead by a two goal margin puts us in a good spot," Timbers coach Caleb Porter said. "But we know how explosive and dangerous that Dallas is, and what they're capable of. So we'll stay very humble and grounded, and we'll get back and prepare for this next game."

Darlington Nagbe, who is back in Portland after his first career call-up to the U.S. national team, stepped into the No. 10 spot for Valeri, who led the team with eight assists in the regular season.

Dallas ended the regular season with a five-game unbeaten streak. Fabian Castillo led the team in the regular season with nine goals and nine assists.

Dallas was dealt a blow this week with the death of Pareja's mother in Colombia on Thursday. Pareja travelled to his native country to be with his family, but was in Portland for Sunday's match. The team wore black armbands in her honour.

"I was really happy to be with my players today and very proud. I'm a person that admires his players a lot, in the good times and the difficult times," Pareja said.

The Timbers peppered Dallas goalkeeper Jesse Gonzalez, who saved a shot by Portland's Lucas Melano before the first minute had elapsed.

Ridgewell, a defender, barrelled in on a diving Gonzalez for his goal in the 23rd minute. It was his first goal of the year.

"It's been annoying not to get one," Ridgewell said.

Asprilla's long shot came from outside the penalty area and sailed beyond Gonzalez's reach into the side of the net in the 53rd minute. It was Portland's 40th post-season goal across all eras.

Dallas narrowed it when David Texeira chipped in a shot that got past Timbers goalkeeper Adam Kwarasey in te 62nd minute. The goal came moments after Ridgewell limped off the field with a tight calf and was replaced by Norberto Paparatto.

Borchers' goal came when a number of Timbers scrambled to push in Paparatto's header as just four minutes of extra time were added.

Following the match, after the rest of the Timbers had left the field, Borchers stood before the north end of the stadium where the Timbers Army supporters' group was celebrating, and he saluted them.

"I just feel like the heartbeat of this club is those fans," Borchers said. "I've felt a special bond with them since I signed, and they've been really good to me. They're an army, and I fell they deserve respect, so I like to salute them."

It is the second straight year that FC Dallas has been to the playoffs. The team went to the MLS Cup final in 2010, but lost 2-1 to the Colorado Rapids.

The Timbers have advanced to the playoffs twice since making the jump to Major League Soccer in 2011 that they've made it to the conference championship. The team fell to Real Salt Lake 5-2 on aggregate in 2013.

In the Eastern Conference finals earlier Sunday, Columbus beat the visiting New York Red Bulls 2-0.

All the teams were rested after a two-week break for international play.