Austin Cook was chased by proven PGA Tour winners all day at the tournament in Georgia.
Now the Arkansas player is one of them.
The 26-year-old tour rookie held off veterans Brian Gay, Chris Kirk, Kevin Kisner and Brian Harman on Sunday at the chilly, windy Sea Island Club's Seaside Course.
Cook closed with a three-under 67 for a four-stroke victory over J.J. Spaun, who carded a 66.
The victory in the final PGA Tour event of the calendar year gave Cook a spot in the Masters next year.
Australia's only player to make the cut, Cameron Percy, had a Sunday to forget with a quadruple bogey eight on the fifth hole among his secen-over par round of 77. He slid down the leaderboard to finish in a tie for 70th.
Cook birdied three of his last four holes after the three-shot lead he began the day with was reduced to just one by Spaun.
He made a 14-foot birdie putt at No.18 to finish at 21-under par.
"There was a lot of stuff going on, mostly up here (tapping his head)," Cook said.
"My ball striking was great and for the most part, my putting was great.
"Holding the nerves down, playing a good round in these conditions. ... I'm so happy."
Gay, the oldest contender of the week at 45, eagled the par-four 18th hole from 161 yards with a nine-iron to card a 68 and break out of a five-way tie for third and finish at 16 under.
Kirk (71) and Kisner (68), past winners of the tournament, local resident Brian Harman (65) and Andrew Landry (67) tied for fourth at 14 under.
