South Africa's Anton Haig matched Greg Norman's 1994 course record in round two with an 8-under 64. He is alone in second place at 9-under-par 135.
Two-time U.S. Open champion Retief Goosen carded his second 4-under 68 in as many days and is tied for third place with James Nitties, who posted a 5-under 67 on Friday. The pair is knotted at minus-8.
Richard Lee shot a 2-under 70 and is in fifth place at 7-under-par 137.
High temperatures and humidity meant difficult conditions for the players on Friday.
Wilson played the second round from the first tee, but parred his first six holes. He added birdies at the seventh and ninth holes to reach 6 under par for the championship.
On the second nine, Wilson flew up the leaderboard. He eagled the par-5 11th, then birdied the par-3 14th for the second time. Wilson, who eagled No. 9 on Thursday, recorded his third eagle of the tournament at the 586-yard 15th.
The Englishman was 11 under par and two strokes ahead until he reached the par-4 closing hole. Wilson's drive came close to water, but it stayed dry. Unfortunately, he could only advance his second shot into heavy rough. By the time Wilson finally reached the putting surface, he had to hole a 6-footer for bogey.
Wilson did convert the bogey putt, which dropped his advantage to one with the weekend to go.
'That was the first hole all week where I lost my composure a little bit,' said Wilson. 'I tried to force the drive and made a mess of it all the way to the green. I managed to hole the six footer for bogey, which was a nice way to finish.'
Wilson will be in search of his first victory on the European Tour. The closest he came was in November of 2005 when he lost the China Open to Paul Casey in a playoff.
At least Wilson won't have to worry about Casey this time around as Casey missed the cut. But Wilson acknowledged that after a little vacation spent studying the teachings of noted sports psychologist Bob Rotella and his continued improvement from last year, he can make it to the winner's circle on Sunday.
'I've been improving each year,' said Wilson. 'Last season I got off to a good start and it sort of fizzled away. I worked on quite a few things from a mental standpoint and everything is coming together now. I'm looking forward to this year. I know I am good enough to play out here but I need to work on my consistency.'
Haig, 20, began on the back nine and birdied the 10th. He left himself 30 feet for eagle at the par-4 13th, and sank the long putt for a two. From there, Haig tallied a pair of birdies and one bogey the rest of his opening nine.
He birdied two, four, six and nine to match Norman's 64, which was later matched by Richard Sterne on Friday.
Perhaps Haig drew inspiration from his Tuesday afternoon practice round partners -- Ernie Els and Retief Goosen.
'It was great,' acknowledged Haig. 'As a youngster I grew up watching Ernie and Retief, awesome players with great golf swings, and their composure on the golf course was awesome to watch. It's just a privilege to be playing in a tournament with them.'
Peter Hanson (72), Adam Bland (67), Kim Felton (68), Richard Bland (70) and Ter-Chang Wang (70) share sixth place at 6-under-par 138.
Overnight leader Brad Kennedy struggled to a 5-over 77 on Friday and dipped into a share of 32nd place at minus-2.
Els shot a 70 in the second round and is part of a group tied for 51st at 1-under-par 143. World No. 4 Adam Scott is also in that logjam.
The 36-hole cut fell at even-par 144 and Casey was the biggest name to miss the weekend. Former Masters champion Mike Weir only managed a 6-over 78 to make the cut on the number.