Five things you need to know about Sounders - Timbers rivalry
The MLS Clásico is one of the oldest rivalries in the US league, dating back to the 1970s, and can be a match for some of the best rivalries in world football.
One of the major rivalries in the MLS is between the Portland Timbers and the Seattle Sounders, and whenever both face each other the league watches. It's also one of the oldest rivalries, starting even before the league came into existence.
Here are five things you need to know about the MLS Clásico.
Rivalry roots
The rivalry started back in the 1970s when the North American Soccer League was in place - throughout the lower division before both teams were granted MLS franchises - and became a long-time animosity in the Pacific Northwest.
It then moved into Major League Soccer in 2011 when both sides met again, and has subsequently grown to become one of the largest rivalries in American soccer.
A 30-year gap
The Sounders joined the MLS in 2009, the Timbers in 2011. In the NASL era, Seattle and Timbers first faced each other in 1975, with the Sounders taking the first victory, although Portland knocked Seattle out of the playoffs later that year.
But it was at the end of 1982 when the Portland Timbers franchise was forced to leave the North American Soccer League due to income issues, with the match on August 22, 1982, where the Sounders claimed a 1-0 victory, becoming the final encounter for nearly 30 years, until their reunion at the MLS in 2011.
Billboard drama
When Portland joined the Major League Soccer in 2011, the rivalry seemed to reignite and took up from where left off, with the Timbers adding fuel to the fire by paying for a billboard just outside the Sounders stadium with: "Portland, Oregon, Soccer City USA 2011" along with the Timbers logo.
The Red Card Wedding
In 2015 a fourth round game which same the Timbers beat Seattle 3-1 is one of the most infamous clashes between this two, with three red cards shown to leave Seattle with seven players on the pitch - they also lost Obafemi Martins to injury with no substitutions left.
On the night of the 'Red Card Wedding', USMNT legend Clint Dempsey was shown a second yellow card but didn't take it very well, grabbing referee Daniel Radford's notebook and throwing it to the ground, before picking it up again just to tear it to shreds. Dempsey was handed a lengthy suspension for the incident.