Australia's John Senden moved into a share of third place behind Nick Watney after the second round of the Wells Fargo Championship, while Tiger Woods failed to make the cut.
In a day of drama at the Quail Hollow Club, former world number one Woods missed the cut by one shot after a two-round total of 144.
It is only the eighth time that Woods has missed the cut and the first time he has missed the final two rounds of a tournament since the 2010 Wells Fargo event.
After losing his ball on the par-five fifth hole, Woods struggled to find his touch, finishing even-par after a second round one-over 73.
Watney carded an eight-under round of 64 in Charlotte to go 12-under at the halfway mark of the tournament.
Webb Simpson holds second place after a score of 68 but he could have been level with Watney if he had not bogeyed the 18th hole.
A four-way tie for third place has Americans Stewart Cink, Ben Crane, D.A. Points and Senden all on 134 going into the third round.
Cink had a share of the lead before two late bogeys left him at 10-under par while Senden had three consecutive birdies early.
First round joint leader Ryan Moore slipped to seventh after a 70 for a two-round total of 135.
Watney, 31, who is looking for his fifth PGA Tour win, had gone nine rounds on the Tour without breaking 70 and had failed to crack the top 10 in all nine of his stroke-play tournaments until this week.
"I think last week was a wake-up call for me," said Watney, who missed the cut in New Orleans.
"And I've worked really hard these five days leading into this event. I think it just shows I'm making progress.
"Who knows what's going to happen this weekend, but I'm really excited for it. More hard work, and hopefully I'll be in this position a lot more."
Of the other Australians to make the halfway cut, Jason Day is tied for 27th at four-under, Geoff Ogilvy is one shot further adrift, Marc Leishman and Aaron Baddeley share 49th at minus two, while Gavin Coles finished the day at one-under.
Compatriots Mathew Goggin, Nathan Green, Stuart Appleby, Robert Alleny, Nick Flanagan and Nick O'Hern all failed to make the cut.