American rookie Jackson Koivun has completed his maiden PGA Tour victory, holding off world number one Scottie Scheffler by three strokes to win the 3M Open on Sunday. The 21-year-old, playing in only his third event since turning professional, produced a composed final round to resist a late surge from the four-time major winner, capping a remarkable rise that comes just two months after he helped Auburn win the US college championship.

Koivun built a three-shot lead with a third-round 61 before extending it to five ahead of the final round at TPC Twin Cities in Minnesota. Scheffler mounted a fierce comeback, carding five birdies on the back nine for a 63, but Koivun held firm with a closing 66 to finish on 25 under par, admitting he had to block out crowd shouts of "Scottie's coming" down the stretch. Americans Denny McCarthy, Brian Harman and Chandler Phillips tied for third alongside Japan's Hideki Matsuyama, five strokes back, while Michael Kim, who fired a 59 on Friday, slipped to a tie for 10th.