Snedeker pulled even atop the leaderboard on the final hole when Stanley found a water hazard and stumbled to a triple-bogey, closing with a round of 2-over-par 74.
Snedeker, meanwhile, carded a 5-under 67 to match Stanley at 16-under 272 through 72 holes.
Both golfers birdied the first playoff hole -- the par-five 18th -- and then moved on to the par-three 16th.
Snedeker caught break when a drive that was heading over the green instead bounced off a television tower, ultimately enabling him to gain a par.
Stanley, however, missed his 4-foot putt for par, handing Snedeker the victory.
John Rollins (71) ended with sole possession of third place two shots behind at minus-14.
Bill Haas (72) and Cameron Tringale (71) knotted for fourth place two shots further back.