Russell Henley fired a six-under par 64 on Friday to grab a four-stroke lead after Friday's second round of the US PGA Wyndham Championship while Olympic runner-up Rory Sabbatini charged.

Henley, a 32-year-old American, had seized the first-round lead with an opening 62 and stood on 14-under 126 after 36 holes at Sedgefield Country Club in Greensboro, North Carolina.