Petterson had a career-best day against #10 University of St. Thomas, recording 14 tackles (8 solo, 6 assists), and an interception against his former team. His interception came at a critical moment in the beginning of the third quarter as St. Thomas had the ball inside Bethel's 15 yard line, thus ending a Tommie drive. Petterson saw limited action as a Tommie last season, but was St. Thomas' second leading tackler as a freshman. This season, he leads Bethel with 68 tackles, which is more than his first two seasons combined.