Johnson Wagner shot a 6-under 64 Saturday to take a two-stroke lead after the third round of the Greenbrier Classic.
Wagner was 14 under overall on the Old White TPC course in West Virginia. Jimmy Walker also shot a 64 and was second at 12 under.
Sweden's Jonas Blixt was 10 under after shooting 67. Texas teenager Jordan Spieth and two others are 9 under.
Wagner entered the day one stroke behind Matt Every. Wagner had seven birdies and a bogey in his round.
No third-round leader has gone on to win the Greenbrier Classic, now in its fourth year.
The tournament has been decided by playoffs the past two years, and Stuart Appleby shot 59 in the final round to win by a stroke in 2010.