Justin Thomas took over the lead at the Workday Charity Open in Dublin, Ohio following a a flawless 66 in his third round.
The major winner sits on 16 under, two shots clear of Norwegian Viktor Hovland, in his pursuit of a 13th PGA Tour victory and has yet to drop a shot.
Midway leader Collin Morikawa is a shot behind Hovland after an even-par 72.
Rickie Fowler climbed 23 places into a tie for eighth as he matched Thomas and Hovland's round of 66 to move to nine under.
Graeme McDowell is four shots further back (in a tie for 29th) after carding a 70 that featured four birdies and two bogeys.
Open champion Shane Lowry slumped to a 74 to drop back to one under overall despite making four birdies.
For the second successive day the Offaly man had a double bogey, to go with four other dropped shots.