Kuchar, who came into the final round ahead by two strokes, led by as many as four shots on the final 18 holes. His birdie on No. 18 put him at 12-under-par 276 for the tournament.
The 34-year-old Florida native, who earlier this year took the WGC-Accenture Match Play Championship, collected his sixth career PGA Tour title.
Kevin Chappell (68) made a late charge, birdying four of his last six holes, but ultimately fell short to end with sole possession of second place at 10-under.
Grabbing third place at 7-under was Kyle Stanley (71).
Scott Stallings (67) and Bill Haas (71) tied for fourth one shot farther back.