Pressing their opponents in the second half, the Timbers got on the scoreboard in the 62nd minute, when Eryk Williamson scored his first of the season.
Playing for the third time in eight days, the Timbers leaned on some newcomers and were overmatched from the outset.
Cutting through the penalty area early in the game, Ricaurte scored off a feed from Ryan Hollingshead for a 1-0 lead with his first goal of the season. Ricaurte slotted a left-footed shot past 19-year-old Timbers goalkeeper Hunter Sulte, who was making his first career MLS start.
FC Dallas went end to end for a 2-0 lead in the 14th minute when Obrian took a long outlet pass from his own goalkeeper, Phelipe, split the Portland back line with his speed and chipped a shot over Sulte. It was Obrian's first goal in his third career MLS game.
The third FC Dallas goal of the first half came in the third minute of stoppage time. Jose Martinez redirected a corner kick on goal with Sulte making the save, but Bressan was able to score off the rebound, his first of the season.
Sealy's late goal, the first of his MLS career in his sixth career game, came two minutes after he entered as a substitute.
In addition to Sulte, who had two saves, the Timbers also gave defender Zac Mcgraw his first career MLS start.
After rallying for a 1-1 tie with Club America at home on Wednesday in the first leg of a CONCACAF Champions League quarterfinal, the Timbers won't fret the result. They will search for an aggregate victory over Club America next Wednesday when they play the second leg at Mexico.