The Utes (5-7, 3-6 Pac-12) doubled their season total with four interceptions of Nick Hirschman, and Dunn extended his NCAA record with his fifth career 100-yard kickoff return - and his fourth this season.
The Buffaloes (1-11, 1-8 Pac-12) finished with their worst record since the school's inaugural 0-4 campaign in 1890. They also failed to win a game at home for the first time since 1920.
The Utes, who had lost all five of their road games coming in, trailed 28-20 heading into the fourth quarter but outscored the Buffs 22-7 down the stretch.
(Copyright 2012 The Associated Press. All rights reserved.)