Kevin Kisner is perfectly placed to end his run of near-misses on the PGA Tour after finishing the penultimate round of the RSM Classic in stunning style to secure a three-shot lead.
Kisner has been beaten in three play-offs this year and was again denied a maiden victory when he finished second to Russell Knox at the WGC-HSBC Champions a fortnight ago.
However, he will begin the final round at Sea Island Resort with a commanding lead, courtesy of a sublime performance over the closing holes on Saturday to move to 16 under.
Overnight leader Chappell, who dropped shots at the second and third, was two behind with five to play but drew level when he followed up Kisner's sole bogey of the day, at the 14th, with a birdie at 15.
Kisner's response was emphatic, however, as the 31-year-old birdied the last three.
A sublime approach to 16 was followed by a tee shot at the par-three 17th that almost found the hole and Kisner then rolled in a 28-foot putt on 18 to complete a round of 64 - the best of the day.
Graeme McDowell, who ended a barren streak of his own with victory in last week's OHL Classic at Mayakoba, is four strokes behind in third after a faultless round of 65.
Alex Cejka birdied three of the last six holes to sit a shot further back but Freddie Jacobson, who had been level with Kisner at the halfway stage, dropped off the pace courtesy of a 71, which left him nine under.