Needing a birdie on the par-4 18th for a 59, Watney drove into the left rough, failed to reach the green with his approach and left his long birdie pitch just short of the putting surface.
The American finished at 22-under 262 and earned $1.3 million in the unofficial PGA Tour event, finishing a stroke ahead of 2011 champion Bo Van Pelt and Robert Garrigus and three ahead of Tiger Woods.
The tournament will become a full-fledged PGA Tour event next year when the tour begins its new season in October after the FedEx Cup.
Van Pelt and Garrigus tied for second, each carding 66 after starting the round tied for the lead.
Woods finished with a 63 to tie for fourth at 19-under with Chris Kirk and Zimbabwe’s Brendon de Jonge. Kirk shot 67, and de Jonge had a 66.
* Sweden’s Peter Hanson won the BMW Masters in Shanghai for his second European Tour victory of the year, shooting a 5-under 67 to hold off Ryder Cup teammate Rory McIlroy by a stroke.
Hanson finished at 21-under 267 on The Masters Course at Lake Malaren and earned $1,166,600 in the European Tour’s richest regular event.
The top-ranked McIlroy, the winner last year when the event was a non-sanctioned exhibition tournament, finished with a 67.
Third-ranked Luke Donald was third at 17 under after a 66, and fellow Englishman Ian Poulter completed a Ryder Cup sweep of the top four spots, closing with a 65 to finish at 16 under.
* Suzann Pettersen won the Taiwan Championship for her second straight LPGA Tour victory, rallying to beat Inbee Park by three strokes.
Pettersen closed with a 3-under 69 in wind and drizzle on the at Sunrise course. The Norwegian finished with a 19-under 269 and earned $300,000 for her 10th LPGA Tour title.
Cristie Kerr was the only American in the top 12, shooting a 73 to tie for sixth at 9 under. Michelle Wie had a 76 to tie for 23rd.
* David Frost won the AT&T Championship, beating Bernhard Langer with a birdie on the second hole of a playoff after overcoming a six-stroke deficit in the final round. Frost and Langer each shot 6-under 66 to finish at 8-under 208 on TPC San Antonio’s Canyons Course.
Second-round leader Mark Calcavecchia had a 74 to finish two strokes back.
* Justin Bolli closed with a 6-under 65 to win the Web.com Tour Championship, making him one of three players who moved into the top 25 on the money list to earn a PGA Tour card for next season.
Morgan Hoffmann of Wyckoff, N.J., who shot a 64, and former St. John’s golfer Andrew Svoboda were among those who earned cards.