Rimando, who missed Real's past two games with a knee injury, was named the player of the week on Monday. His performance against the Timbers included three big saves, with two of those coming in the final five minutes.
Rimando's first save of the night came in the 19th minute, when he punched a shot from Portland forward Darlington Nagbe over the crossbar.
Late in the match, just after RSL had taken the lead on Ned Grabavoy's first goal of the season, Rimando came up big again. In the 85th minute, he made a kick save on a shot from Portland's Alvas Powell from around eight yards out.
Then in the 88th minute, Rimando stonewalled the Timber again, this time stopping a left-footed shot from Gaston Fernandez that curled towards the upper left corner of the goal.