The Portland Timbers weathered a furious comeback to clinch an Audi 2018 MLS Cup Playoffs Western Conference Semifinals series win over the Seattle Sounders, despite losing 3-2 on Thursday at CenturyLink Field in the second leg but prevailing 4-2 on penalties in a shootout.

The No. 5-seeded Timbers will move on to the Western Conference Championship against Real Salt Lake or Sporting Kansas City, while the Sounders' season is over.

After a first half in which the teams exchanged fouls and little in the way of flowing play, the second 45 found Seattle settling into the game and finding a rhythm in Portland's half.

After Sounders star forward Raul Ruidiaz missed the mark in minute 54, he didn't miss the second time around. Portland goalkeeper Jeff Attinella failed to catch a long cross, and the Peruvian striker pounced on the loose ball, burying it to flip the series in Seattle's favor.

But the Timbers didn't give up, and took control of the series once again when Sebastian Blanco buried a low blast from just outside the box after a counterattack and patient build-up in the 78th minute.

Ruidiaz had the last laugh in regulation, however, as he came up with his third consecutive goal for Seattle in the series, hitting a volley through traffic in the 93rd minute to knot up the series at 3-3 on aggregate goals, with neither team holding an edge on the away goals tiebreaker. As a result, the game went to 30 minutes of extra time.

In extra time, Portland grabbed an early advantage, as substitute Dairon Asprilla scored with a back post header from Diego Valeri's cross, but a handball at the other end by Blanco allowed Nicolas Lodeiro to tie up the series from the penalty spot four minutes later.

Ruidiaz hit the back of the net for a third time in the second period of extra time, but the goal was waved off due to a handball infraction on the play.

In the ensuing penalty kick shootout, Seattle's Will Bruin hit the post, while Osvaldo Alonso saw his attempt saved. Stefan Frei's save on Portland's Liam Ridgewell briefly kept the Sounders' hopes alive, but Asprilla was able to end the Sounders' season despite Frei getting a hand on his series-winning attempt.

Goals

68' – SEA – Raul Ruidiaz | WATCH

78' – POR – Sebastian Blanco | WATCH

90+3' – SEA – Raul Ruidiaz | WATCH

93' – POR – Dairon Asprilla | WATCH

97' – SEA – Nicolas Lodeiro (PK) | WATCH

Three Things

THE BIG PICTURE : For the second time in MLS history, the Timbers got the better of the Sounders in the MLS Cup Playoffs. All things considered, it was a coin flip, as a sleepy and ill-tempered opening 60 minutes turned into a goalfest, with the teams trading haymakers to keep everyone on the edge of their seat.

: For the second time in MLS history, the Timbers got the better of the Sounders in the MLS Cup Playoffs. All things considered, it was a coin flip, as a sleepy and ill-tempered opening 60 minutes turned into a goalfest, with the teams trading haymakers to keep everyone on the edge of their seat. MOMENT OF THE MATCH : He also had the clinching penalty, but Asprilla's early goal in extra time set the tone that carried the Timbers through to the next round. In the process, the Colombian burnished his reputation as a playoff specialist.

: He also had the clinching penalty, but Asprilla's early goal in extra time set the tone that carried the Timbers through to the next round. In the process, the Colombian burnished his reputation as a playoff specialist. MAN OF THE MATCH: Ruidiaz showed off his best qualities once against a striker, a clinical touch in front of goal in the key moments. His brace not only jumpstarted the Sounders' rally, but it turned the series into an entertaining clash that won't soon be forgotten.

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