Osvaldo Alonso with Diego Valeri - Seattle Sounders - 2013 Playoffs

The Portland Timbers nabbed a spot in the Audi 2018 MLS Cup Playoffs' Western Conference Semifinals via a Knockout Round victory over FC Dallas on Wednesday night. A Real Salt Lakewin on Thursday night and the playoffs' re-seeding format have paved the way for the Timbers to meet a familiar foe: the Seattle Sounders.

This storied Cascadia rivalry has only taken place once before in the MLS Cup Playoffs. A 2013 Western Conference Semifinal pitted the top-seeded Timbers against the Sounders, who blanked Colorado at home as a No. 4 seed to advance to that stage in Clint Dempsey's first season with the Rave Green. Portland would take both legs of the series, prevailing 5-3 on aggregate before falling short of their MLS Cup aspirations at the hands of RSL.

Leg 1: Portland 2, Seattle 1 (Nov. 2, 2013)

Making their MLS Cup Playoffs debut, the Timbers were immediately faced with a tall task: beating the Sounders at CenturyLink Field, something they had never done in MLS.

An early strike from Ryan Johnson did wonders to ease tension for the visitors, who then took a two-goal lead through Darlington Nagbe in the 67th minute. The Timbers looked to be firmly in command of the series heading home for the second leg, but a volley from Ozzie Alonso in the 90th minute kept the Sounders' hopes alive.

Leg 2: Portland 3, Seattle 2 (Nov. 7, 2013)

Yet again Portland jumped on Seattle early, with Rodney Wallace nearly putting the hosts ahead in the third minute. A Sounders hand ball in the penalty area would set up the Timbers go-ahead goal 16 minutes from halftime, converted by Johnson. Diego Valeri's sliding effort in the 44th minute and Futty Danso's header two minutes into the second half made for a commanding Timbers advantage. Though Seattle were able to score twice in the second half, Portland saw out the series victory. They would go on to lose to RSL in the Western Conference Championship.