3M Open final leaderboard

-25 J Koivun (US); -22 S Scheffler (US); -20 D McCarthy (US), B Harman (US), C Phillips (US), H Matsuyama (Jpn)

Selected others: -17 S Power (Ire), G Woodland (US) M Kim (US); -16 Knapp (US); -13 J Parry (Eng)

Full leaderboard

American newcomer Jackson Koivun maintained composure to defeat Scottie Scheffler by three shots and secure his initial PGA Tour triumph at the 3M Open on Sunday.

In only his third event after turning pro, Koivun built a three-stroke advantage on Saturday with a 10-under 61.

The 21-year-old extended his lead to five during the final round at TPC Twin Cities in Minnesota, until world number one Scheffler mounted a challenge.

The multiple major champion started the back nine with three consecutive birdies and added two more in the last three holes for an eight-under 63, finishing two shots behind his fellow American Koivun.

Previously the top amateur globally, Koivun stayed steady despite the pressure, recording his fifth birdie of the round at the 16th hole and closing with a five-under 66 to end at 25 under par total.

"I felt some tension on the 18th hole," Koivun remarked. "Throughout the gallery I heard mentions of 'Scottie's coming, Scottie's coming'."

"I focused on ignoring that and continued with the game I was capable of, sinking some solid putts down the stretch."

A group of three Americans - Denny McCarthy, Brian Harman and Chandler Phillips - ended five shots back in a share of third alongside Japan's Hideki Matsuyama.

Michael Kim posted a 12-under 59 on Friday, yet the American ended tied for 10th following closing scores of 70 and 69.