Gossett sank a four-foot par putt on the 72nd hole to capture the John Deere Classic in Silvis, Ill.
Gossett became the 15th first-time PGA Tour winner at this tournament. He also became the first person since Tiger Woods at the 1996 Las Vegas Invitational to win a tour event after receiving a sponsors exemption.
Gosset comments on his first win
'It's good to be in that kind of company,' said Gossett, who earned $504,000. 'It's a telltale sign that I'm doing something right, and I'll stay with it and continue working on my game.'
Gossett shot a final-round 5-under-par 66 at the TPC at Deere Run to finish at 19-under 265, one shot clear of Briny Baird, who also shot a Sunday 66.
Gossett, the 1999 U.S. Amateur champion, entered the event as a member of the Buy.Com Tour. He was relegated to the developmental tour despite shooting a 59 in the 2000 PGA Tour Qualifying Tournament.
In 12 Buy.Com starts this season, Gossett had recorded six top-10 finishes, including four straight heading into this week.
The 22-year-old from Germantown, Tenn., led from start to finish after opening in 64.
He started the final round leading Baird, Bradley Hughes and Paul Stankowski by one. Stankowski shot a 1-under 70 to finish in seventh place, while Hughes struggled to a 72 and a tie for 10th.
Playing in the final group, Gossett and Baird were tied at 18-under through 14 holes. Gossett then birdied the 15th to go up one at minus-19.
Baird fell two strokes back when he failed to get up and down after missing the green at the par-3 16th. But he recovered with a two-putt birdie on the par-5 17th to get within one of the lead with one hole to play.
At the par-4 finishing hole, Gossett drove into the right rough and Baird found the left fairway bunker.
Baird managed to hit his approach shot 20 feet below the hole, while Gossett missed the green long. Gossett chipped up to four feet, leaving Baird with a chance to force a playoff. Baird left his attempt short. Gossett then drilled his putt center-cut to claim victory No. 1.
'It's a little different than the dream,' said Gossett. 'In the dream, you always do something spectacular. You're always hitting a nice high 4-iron over water to three feet to win on the last hole. But I thought making a (four-foot putt) right in the middle for the win, I thought that was pretty close to the dream, actually.'
Gossett will now take his newly earned PGA Tour card with him to Castle Rock, Co., site of the upcoming International.
Gossett made his professional debut at the Castle Pines Golf Club a year ago.
Full-field scores from the John Deere Classic