Entering the final round tied for 50th place, Tryon shot a 6-under-par 66 to finish at 18-under 414 for the six-day event.
"It hasn't really sunk in yet because after all the pressure today and all the playing I am just kind of worn out but tonight when I go to sleep I know I will be on the PGA Tour and it's just so unbelievable," Tryon said.
Tryon, an Orlando, Fla., native, needed the big round Monday since the top 35 plus ties in the 166-player field earned tour cards.
In March, Tryon, then 16, became the youngest player in 44 years to make a PGA Tour cut at the Honda Classic. He also led after the first round at the B.C. Open in July and tied for 39th.
Pat Perez won the event, shooting an even-par 72 to capture the tournament at 27-under 405 by one stroke over Bob Burns, Pete Jordan and Kenneth Staton. Along with gaining his first card, Perez captured the $50,000 first prize and a higher priority for getting into the tournaments early next year.
A member of Arizona State's national championship team in 1996, Perez made $124,818 in 26 Buy.com starts this past season.
Robert Gamez, a two-time winner on the PGA Tour, was unable to capture his card after shooting a 2-over 74, to miss by one stroke.
Among the notables that earned their cards were Tommy Armour III (409), Russ Cochran (410) and Gary Nicklaus (411), defending medallist Stepehen Allen (413) and former NCAA champion Luke Donald (414).
Tommy Tolles (419) and Gabriel Hjerstedt of Sweden were two notables who failed to secure their cards.