The Revolution, appearing in the postseason for the first time since 2009, entered the match with a 501-minute regular season goal drought against Sporting Kansas City, a streak that reaches back to the 2011 season.
The clubs will play the second leg of the series on Wednesday at Sporting Park in Kansas City, Kan. The team with the most aggregate goals in the two matches will advance to the conference finals.
Timbers 2, Sounders FC 1 • In Seattle, Ryan Johnson flicked in a header early in the first half, and Darlington Nagbe scored midway through the second half as Portland beat Seattle in the first leg of their Western Conference semifinals series.
The third-year Timbers, playing in their first MLS postseason contest, need just a draw in Wednesday's second leg at Portland to advance to the conference finals.
Osvaldo Alonso scored in the 90th minute for the Sounders.
The Timbers went unbeaten through their last eight games of the regular season (5-0-3) to secure the West's No. 1 seed.