Oregon scored the game's final six points in the semifinals of the Global Sports Classic. The Ducks will meet No. 20 Cincinnati in the tournament finals on Saturday while UNLV will face Iowa State in the third-place game.
The Rebels had the lead and appeared to be in control when Anthony Bennett broke free for what would have been an uncontested layup with 1:13 to play.
Bennett missed the easy shot, however, and Oregon's Carlos Emory hit a jumper 14 seconds later that tied it.
After a 3-point miss by UNLV's Justin Hawkins, Dotson made his jump shot that boosted the Ducks into the lead. Dotson finished the scoring by making two free throws with 6 seconds remaining.
Dotson led Oregon (5-0) with 19 points and Emory had 16 off the bench. Bennett scored 22 points in pacing the Rebels.