The Ducks overcame a 10-point deficit in the second half of their Pac-12 opener to remain unbeaten.
Dotson's two free throws with 12 seconds remaining in regulation brought about the overtime period and it appeared there would be a second extra stanza as Utah worked for a final shot in the closing moments.
Dotson, however, came up with a steal while defending Dallin Bachynski and drove to the basket to give the Ducks their 13th win in as many games this season.
Richard Amardi led Oregon with 14 points and eight rebounds while Dotson finished with 11 points. The Ducks shot 40 percent from the field and limited Utah to 38 percent in the defensive duel.
Utah (11-2, 0-1 Pac-12) was paced by Jordan Loveridge with 21 points.