(Reuters) - Kevin Kisner enjoyed a one-stroke lead over fellow American Xander Schauffele halfway through the final round at the Tour Championship in Atlanta on Sunday.
Kisner negotiated the front nine at East Lake with two birdies and one bogey to improve to 11 under par at the turn.
Schauffele was alone on 10 under, while overnight leader Paul Casey slipped two strokes behind after struggling on the outward half.
The Englishman racked up three bogeys to fall to nine under, sharing third place with Americans Justin Thomas and Russell Henley.
Jordan Spieth, boosted by an eagle at the par-four 10th, was three shots behind with only four holes left.
Spieth remained the favorite to win the season-long FedExCup points race and its $10 million bonus, but Thomas was also in contention.
Reporting by Andrew Both in Cary, North Carolina; Editing by Christian Radnedge