India, July 28 -- Jackson Koivun felt the nerves but never flinched, securing his first PGA Tour win in the face of a strong finish by the world's top-ranked player and clear fan favorite in Scottie Scheffler.

Koivun won the 3M Open by three strokes Sunday in only his third start as a professional, holding off Scheffler with a closing 5-under 66 for a tournament-record 25-under 259 total.

"All throughout the crowd I kept hearing, Scottie's coming. Scottie's coming,'" the 21-year-old Koivun said. "I just tried to tune that out and keep playing the golf I knew I could."

Scheffler, who played five groups ahead of Koivun, surged into contention with a 63 but settled for his fifth runner-up finish this season. His lone win this year was in ...