Xander Schauffele closed with a birdie to fire a six-under par 66 and seize a one-stroke lead after Saturday's third round of the Charles Schwab Challenge, the first PGA Tour event since the coronavirus shutdown.
The 26-year-old American stood on 13-under par at Colonial Country Club in Fort Worth, Texas, with five rivals deadlocked behind him on 12-under.
South Africa's Branden Grace and Americans Gary Woodland, Justin Thomas, Collin Morikawa and Jordan Spieth were one adrift, with Americans Daniel Berger and Harold Varner another stroke further back.
World number one Rory McIlroy of Northern Ireland shot 69 to join a pack on 10-under that included England's Justin Rose, Mexico's Abraham Ancer, Canadian Corey Conners and Americans Patrick Reed and Bryson DeChambeau.
The tournament marks the return of the US golf season after a 91-day layoff since early March due to the coronavirus pandemic.
Schauffele edged out of the pack to take a one-shot lead