You don't see a fourth-round US Open Cup matchup like this very often.
Not only are two MLS sides meeting at this early stage of the tournament, it's two clubs who share as much enmity between them as any duo in North American soccer. Seattle and Portland are heated participants in the annual Cascadia Cup, and now their fans are being treated to a special USOC edition of the rivalry at the Starfire Sports Complex in Tukwila, Washington.
The Sounders are defending their 2014 title, their fourth in their six years of MLS play, while the Timbers believe that they can launch a deep run of their own by knocking off the current holders.
