The Timbers (13-5-15), who clinched the first post-season berth in team history earlier Saturday, moved one point behind Sporting Kansas City in the race for the best record in the MLS.
Second-place RSL (15-10-8) used the result to stay one point Portland in the West.
They will make the post-season if the Los Angeles Galaxy falls to San Jose Sunday.
Lytro unveils camera that can focus a photo after shooting it
'How to Train Your Dragon 2' releases 5-minute clip