The holdover from the club's lower-league days came on as a substitute and netted the first MLS goal in team history.
Christian Ramirez goes into the record books as the first goal scorer in Minnesota United's Major League Soccer history.
Ramirez, who became a star with Minnesota in NASL, came off the bench in the 69th and took just 10 minutes to find his first, and the club's first, MLS goal.
The striker's goal came after he picked up a ball at the top of the box. With Portland defender Liam Ridgewell calling for offside rather than closing down, Ramirez turned and slotted the ball into the bottom corner.