The Wake Forest junior from Raleigh closed 68-272, making a 6-foot par putt on the closing hole to avoid a three-way playoff with Southern California junior Tom Glissmeyer and Seung Su Han of South Korea.
Glissmeyer tied the Country Club of North Carolina's Dogwood course record of 63, set by Orlando's Sam Saunders in the opening round three days earlier.
Glissmeyer birdied five of the first six holes. On the 18th hole, his 25-foot eagle putt fell just short.
Simpson needed only a par on the uphill par-5 hole to win. He bunkered his drive and sent a pitching wedge five yards over the green. He chipped out of the rough to within 6 feet then made the par putt.
Simpson, who won the Southern Am two years ago in Myrtle Beach, now has a spot in the 2008 Arnold Palmer Invitational.
'It was a tough day,' Simpson said. 'It was nice to have my dad on the bag to calm me down every now and then. The wind blew and I felt the pressure to perform for all the people out there pulling for me.'
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