Graham DeLaet and Luke Donald will both begin Round 3 at 10-under. He made up for the mistake with an outstanding flop shot to end his day with a hole-out birdie.
Kim rolled in nine birdies Thursday and had just one bogey as she rocketed from a tie for 48th after the first round to become the co-leader with Thailand star Ariya Jutanugarn when play was suspended for the day. "I proved that the last couple of holes". "The grass lends itself to be enough to create some spin. I think that was the little bit of confidence I needed", DeLaet said. Then Simpson cooled off, with 11 pars and a bogey on the 16th that dropped him two shots behind.
He is looking for his first win in 12 appearances at Harbour Town.
Dufner, 40, has not had a top 10 in nine PGA Tour starts in the calendar year and tied for 33rd in the Masters last week.
"I feel like this golf course has always been a good set up for me", Dufner said. I was really happy how I played on the back nine.
The last time Donald held a lead after 36 rounds was at the 2011 RBC Heritage, where he fell in a playoff against Brandt Snedeker.
The Canadian used three birdies and an eagle to jump to the top of the leaderboard.
That tied the English former world number one with early starter DeLaet, who holed out a wedge shot from 109 yards to eagle the par-four ninth on his way to 67 on the Harbour Town layout. "And I hit a great shot, but obviously there's an element of luck".
Donald's Ryder Cup team-mate Ian Poulter is tied with former US Open victor Webb Simpson in a share of third on eight under after both carded second rounds of 68.
Canadians Adam Hadwin and Mackenzie Hughes have won PGA Tour events this season.
With the golf course in excellent shape, many players are saying the best it's ever been, and Harbour Town's familiar wind is lying down, so more players than usual have had the chance to shoot low rounds.
"But it is just good for all us in Europe and everyone playing golf back in Britain and Europe a big lift".
First-round leader Bud Cauley followed his 63 with a 72 and was in a group of five at 7-under that included former PGA Championship victor Jason Dufner and Sam Saunders, the grandson of golf's late king, Arnold Palmer.