Jackson Koivun holds off Scheffler to win 3M Open in third professional start

US golfer, 21, finished at 25-under par for three-shot win Scheffler closed with 63 to finish second in Minnesota The rookie Jackson Koivun shot a five-under-par 66 to stave off a charging Scottie Scheffler and win ⁠on the PGA Tour for the first time at the 3M Open on Sunday at Blaine, ⁠Minnesota. Koivun, 21, finished ⁠at ​25 under par for a three-shot victory over Scheffler, who closed with a 63 at TPC Twin ⁠Cities. Less than two months ago, Koivun was helping Auburn to its second NCAA…