Nicolas Lodeiro was at the double as the Seattle Sounders routed for FC Dallas 3-0 in the first leg of their MLS Western Conference semifinal, while the New York Red Bulls went down to a Matteo Mancosu stunner.
Dallas won the Supporters' Shield after claiming the most regular-season points as the Sounders scrapped through their elimination playoff.
But the Sounders put their highly-fancied opponents to the sword in Seattle on Sunday, thanks to Lodeiro and Nelson Valdez.
Valdez, who came off the bench to send Sporting Kansas City packing last time out, broke the deadlock five minutes into the second half.