SEATTLE — Chad Marshall headed in a corner kick in the 24th minute, and the Seattle Sounders beat the Chicago Fire 1-0 on Wednesday night to get back into the MLS playoff picture.

The Sounders (12-13-5) have 41 points and climbed into a tie with idle Portland for the sixth and final playoff berth in the Western Conference. Seattle still has one game at hand on the defending champion Timbers, and also has one more win. Total wins is the first tiebreaker.

Chicago (6-15-9) was eliminated from postseason contention. The Fire have four games remaining and can finish with no more than 39 points. D.C. United is sixth in the East with 40 points after beating Columbus earlier Wednesday.

Andreas Ivanschitz set up Marshall’s fourth goal of the season with a corner kick from the right wing side. The ball floated to the top right corner of the 6-yard box, and Marshall went up with a twisting header that went into the far side of the net, way beyond the reach of goalkeeper Sean Johnson.