After making just one bogey over his first 54 holes, Austin Cook made his second of the week at the par-4 second hole in the final round at the RSM Classic in St Simons Island, Georgia. Just like that, his three-shot lead had shrunk to one, and suddenly the pressure was on for the US PGA Tour rookie with just 13 career starts.

Instead of letting one slip away, Cook showed experience beyond his years, posting a final-round three-under 67 without dropping another shot on his final 16 holes. His 21-under 261 total at Sea Island Golf Club was good enough for a four-shot victory, the first of his career on the US Tour.

Cook made just one birdie in his first 14 holes, opening the door for those within striking distance. But Cook slammed it shut on the last four holes, making birdie at the 15th, 17th and 18th to finish in style. His 23 birdies for the week were more than anyone else in the field.

Cook, 26, had very little experience on tour entering the week, but made the most of his limited chances. In 2015, he played in seven events, three of which he Monday qualified for, and finished inside the top-25 five times, including a T-6 at the Barbasol Championship. Today’s win comes in the fourth start of his first full season as a member of the tour, and earns him exemptions into the Masters, the Players Championship and the US PGA Championship, among others.

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Finishing four behind at 17-under 265 was J.J. Spaun, who carded a four-under 66. Spaun had closed the gap thanks to a four-under start in his opening 10 holes, but ran into some troubles on the inward nine, dropping shots at the 11th and 17th holes. The outright-second finish is his best on tour, coming in just his 36th career start.

Through 14 holes, Brian Gay was even-par for the round and 14-under for the tournament, a total that would have put him in five-way tie for third. But Gay jumped up the leaderboard with two eagles on his final four holes, including a 147-metre hole-out from the fairway at the par-4 18th to post a two-under 68. He finished alone in third at 16-under 266, giving him his best result since last season’s Barbasol Championship, where he tied for third.

Brian Harman, Kevin Kisner, Andrew Landry and Chris Kirk tied for fourth at 14-under 268. The lone Australian to see weekend was Cameron Percy, who cost himself some extra prizemoney with a closing 77 to fall into a tie for 70th.

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