Luis Amarilla also scored what proved to be the game-winning goal for Minnesota, while goalkeeper Tyler Miller, who helped lead Los Angeles FC to the Supporters' Shield in 2019, made two saves in his debut for the Loons.
The Loons took a 1-0 lead in the 51st minute on Molino's 24th career goal. The score came at the end of a two-on-one break that saw Finlay make a crossing pass from the right wing for Robin Lod. Clark smothered it at the left edge of the box, but Molino poked the ball out of Clark's grasp and then shot it straight into the net.
Portland tied it five minutes later on Valeri's penalty kick, his 19th in 24 career attempts. The goal was set up when Minnesota's Ike Opara, the reigning MLS Defender of the Year, tripped Felipe Mora in the right corner of the box for a foul.
But 20 minutes later, Minnesota took control with two goals in the span of two minutes. Amarilla got the first in the 76th minute when he headed Finlay's crossing pass from the right side of the box underneath Clark.
Molino then notched his brace in the 78th minute. Finlay flicked a half-volley over his head to the unguarded Molino in the center of the box, where he one-timed a right-footed volley past Clark.
Portland finished with a 7-2 edge in shots during a scoreless first half that featured just one shot on goal, a weak left-footed attempt by Yimmi Chara from the center of the box in the 30th minute that Miller easily stopped.
The Timbers' best chance at scoring came in the fourth minute when midfielder Cristhian Paredes had an attempt just outside the middle of the 6-yard box that he fired past the right post.
Minnesota's best chance came in the 33rd minute on a corner when Amarilla's right-footed attempt from the right side of the 6-yard box went over the top of a wide-open right side of goal.