Osvaldo Alonso has struck late at Centurylink Field to give Seattle Sounders hope coming back from behind to defeat Portland Timbers and reach the MLS Western Conference final.
Caleb Porter's men will take a 2-1 lead into Thursday's second leg, with the Sounders needing what would be a first win in eight games to keep their faltering MLS Cup dreams alive.
Ryan Johnson got the visitors up and running in the 15th minute with a header from Jack Jewsbury's cross.
Things got worse for the hosts in the second half, as Darlington Nagbe stole in front of his marker before burying the ball between Marcus Hahnemann's legs.
However, Alonso has set up an exciting finale at Jeld-Wen Field after latching onto Shalrie Joseph's flick on to fire past Donovan Ricketts in the final minute.
