Rickie Fowler, the winner of the 2012 Wells Fargo Championship, shot a four-under 68 in the third round at Quail Hollow on Saturday to take a one-stroke lead.
"It's been fun to see [the course] transition," said Fowler, who is at nine-under par 207. "We were going to get some good weather. Once the greens start to dry out like they did today, it's a lot tougher to get close to the hole."
Roberto Castro bogeyed the final hole to fall from a tie for the lead and will enter the final round alone in second, one stroke behind Fowler.
Andrew Loupe, the leader through 36 holes, double-bogeyed the 18th hole and shot a two-over par 74 to fall to six-under for the tournament. He is tied for fifth.
World No. 10 Justin Rose shot a three-under 69 and is tied for fourth with James Hahn at seven-under, two shots off the lead.
Phil Mickelson shot a four-over 76, dropping to one-under through 54 holes. Mickelson was at even-par and tied for seventh until the 18th hole, where he put his second shot in the water, and closed with a quadruple bogey.
Rory McIlroy shot a one-over 73, featuring four bogeys, a double bogey, and a remarkable 79-foot birdie putt on the par-three 17. He is tied for 19th at one-under, and eight shots off the lead.