Rory McIlroy is four shots behind leader Xander Schauffele after the second day at Wells Fargo in Charlotte.
The Northern Irishman shot a faultless 18 holes on Friday at Quail Hollow with three birdies for a three under par 67 to hold his spot in second place, tied with Australian Jason Day.
McIlroy told reporters that he felt like he could have "squeezed a couple more out of the round" but was happy that he went bogey free.
He said: "I'm comfortable here. I think I can take advantage of how far I hit it off the tee.
"I think this golf course really lends itself to driving distance. So the fact that I'm comfortable, the length off the tee, and then I've had so many good memories here, just I feel positive vibes, I feel good about myself when I'm walking around here."
American Schauffele extended his lead to four strokes, grabbing five birdies and a bogey on the last hole of the day to sit on top with 11 under par.
Day sits tied with McIlroy heading into the third round after he shot six birdies and two bogeys.
Seamus Power is tied for 40th on one over while Shane Lowery is tied for 58th and four over. There is no cut for the event.