J.B. Holmes fired a six-under-par 66 to ensure he will take a one-stroke lead into the final round of the Wells Fargo Championship at Quail Hollow.
Holmes' round, which featured seven birdies and just a solitary bogey, saw him post a clubhouse total of 13-under-par.
Martin Flores looked set to match him but, having found water from the tee, would make a bogey at 18 which saw him finish one back.
Just two strokes off the pace is Phil Mickelson who charged through the field on 'moving day' with a quite superb round of 63.
The five-time major champion enjoyed a purple patch on the front nine as, between the third and eighth holes, he produced five birdies and an eagle, eventually reaching the turn in just 29 shots.
Two further birdies followed on the back nine as he completed a blemish-free round that puts him in contention for his first victory since his triumph at last year's Open Championship.
A delighted Mickelson said afterwards: "This was a really good day from start to finish. I drove the ball well, my iron play was on, short game was sharp and I made a lot of putts.
"I played a really good round and it feels good because it's been a rough year for me this year, I haven't been healthy early on, I haven't put it all together and to have a good round today and a good round in the first round is a good start.
"I made a couple of good ones (putts) early on that were long and tough on holes four and six that really got me ahead for the round and then I took advantage of the birdie holes."
Kevin Kisner is on his own in fourth at 10-under, while England's Justin Rose (71) and American Jason Bohn (67) are one further adrift.
Rory McIlroy ensured he has an outside chance of fighting for a second victory at the tournament after an excellent 65 moved him up to six-under overall.
McIlroy's exploits revived memories of his win at Quail Hollow in 2010 when, just as he did this year, he survived the halfway cut on the number, before going on to shoot 66-62 over the weekend to clinch an incredible success.