SEATTLE – Sounders FC and the Portland Timbers have met in the playoffs three times before in the histories of the two clubs. On Saturday at CenturyLink Field, they showed all of the qualities of the decades-old rivalry in the first leg of the Western Conference Semifinal series as the two sides battled all the way to the final whistle and Portland left with a 2-1 lead in the series.

Ryan Johnson and Darlington Nagbe staked the Timbers to a 2-0 lead, but Osvaldo Alonso pulled one back to keep the series close heading to Portland for the second leg on Thursday.

“I thought from the run of play we did enough to deserve a result, but our finishing wasn’t as sharp as Portland’s,” Sounders FC Head Coach Sigi Schmid said, noting that Seattle held nearly 60-percent of possession and outshot Portland 20-10. “Our finishing needed to be a little bit better.”

Seattle dominated possession over the first 15 minutes, but the Timbers struck first.

Jack Jewsbury made an overlapping run into the right corner and crossed it to the near post where Ryan Johnson flicked a header past Marcus Hahnemann for the 1-0 Portland lead.

Seattle got several set-play opportunities in the first half, but was unable to even the tally.

Clint Dempsey had two dangerous free kicks that threatened Portland goalkeeper Donovan Ricketts in a nine-minute span. In the 20th minute, his right-footed effort cleared the wall and was bound for the net, but Ricketts got his hand to it to parry it over the bar for a free kick. The second came in the 29th minute, as he sent his shot off the top of the crossbar and over for a goal kick.

Seattle also had eight corner kicks, but wasn’t able to generate chances off of them and went into the half trailing 1-0.

Portland added to the lead in the 67th minute, as second-half sub Kalif Alhassan found Darlington Nagbe streaking into the box. Alhassan slotted Nagbe in from the right side as Nagbe ran across the front of the Seattle defense. He touched it past Djimi Traore then fired a shot past Marcus Hahnemann for the 2-0 lead.

On both goals, Schmid pointed to defensive errors that created the opportunities.

“On the second goal, there were a number of times where I thought we could have won the ball,” Schmid said. “On the first goal, early in the game we gave too much space to Jewsbury. So Jewsbury got a number of touches and you saw in the second half that really disappeared. He got forward, Ryan Johnson makes a good near post run and we don’t follow him all the way and he gets the ball first.”

Seattle looked to pull one back in the 75th minute when it got the ball into the box on a long free kick. It bounced around in front of the goal and Dempsey turned a left-footed shot from 10 yards out, but skipped just wide of the post.

“I had my chances tonight. I was happy with the looks that I got and getting touches with the ball,” said Dempsey, who finished the night with a game-high six shots. “It was just one of those nights that it wasn’t going to go in for me.”

In the final minutes of the match, Seattle continued to press for a goal.

In the 87th minute, Mauro Rosales sent first a free kick, then a corner kick into the box from the right side. Dempsey got his head to the corner kick and bounced his shot off the turf, but missed just over the crossbar.

In the 90th minute, Alonso finally got them off the mark.

Brad Evans sent a long throw in from the right side. Shalrie Joseph got his head to it, flicking it into the center of the box, where Alonso rifled a left-footed shot past Ricketts for the goal, making it 2-1.

In the fourth minute of stoppage time, Dempsey nearly equalized when he got his head to a cross from Marc Burch, but Ricketts made the save to end the first leg with a one-goal advantage.

“The goal at the end of the game was very important for us because it gives us the opportunity to go down there and win. We showed that we can carry the game to them,” Schmid said. “So we just have to go down to Portland, carry the game to them and score.”

Lamar Neagle was shown a yellow card in the 47th minute for a tackle in the midfield. It was his second caution of the postseason, meaning he will be unavailable for the second leg, however, Seattle expects to have defender DeAndre Yedlin back from an ankle injury and may have forward Obafemi Martins available as well.

Scoring

Sounders FC – Osvaldo Alonso (Shalrie Joseph, Brad Evans).

Timbers – Ryan Johnson (Jack Jewsbury, Diego Chara) 15; Darlington Nagbe (Kalif Alhassan) 67.

Discipline

Sounders FC – Lamar Neagle (caution) 47.

Timbers – Rodney Wallace (caution) 44; Ben Zemanski (caution) 84.

Lineups

Sounders FC – Marcus Hahnemann, Zach Scott (Mauro Rosales 63), Jhon Kennedy Hurtado, Djimi Traore, Leo Gonzalez (Marc Burch 84), Brad Evans, Osvaldo Alonso, Clint Dempsey, Adam Moffat (Shalrie Joseph 77), Eddie Johnson, Lamar Neagle.

Timbers – Donovan Ricketts, Jack Jewsbury, Mamadou Danso, Pa Modou Kah, Michael Harrington, Diego Chara, Diego Valeri (Kalif Alhassan 61), Will Johnson, Darlington Nagbe (Ben Zemanski 73), Ryan Johnson (Jose Valencia 83), Rodney Wallace.