American Keegan Bradley shot the lowest round for the second day in a row at the Wells Fargo Championship to take a two-shot lead into the final day.
Bradley followed up his second-round 65 with a 67 at TPC Potomac in Maryland for an eight-under total.
His nearest challenger is compatriot Max Homa, with India’s Anirban Lahiri and American James Hahn on four under.
Bradley, the 2011 US PGA champion, is chasing a fifth PGA Tour win – his last came in 2018 at the BMW Championship.
England’s Matt Fitzpatrick is three under after a 71 while Northern Ireland’s Rory McIlroy is six shots off the lead on two under after a 68 that helped to make amends for his second-round 73.
Halfway leader Jason Day of Australia slipped down the leaderboard after a 79 that included two double bogeys and he is now on one under.