Watney, who set a course record Saturday with an 8-under 62, finished at 13-under 267 -- two ahead of second-round leader and 2007 champion K.J. Choi.
The 30-year-old Watney used a front-nine total of 32 to grab sole possession of first place. He played the tourney's final 27 holes at 12-under par with 10 birdies, an eagle and no bogeys.
Choi double-bogeyed the 15th to fall two back, eventually registering a 3-under 67 to take second place at minus-11.
Sharing third place at minus-9 were Charles Howell III (66) and Adam Scott (68).
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