A resurgent Ross McGowan fired a brilliant 62 to set the clubhouse target and open up a three-shot lead during round two of the Joburg Open.
The Englishman was playing just his 27th European Tour event in the last five seasons after losing his card in 2011 and seeing his career stalled by a succession of injuries.
McGowan made his breakthrough in 2009 with a win at the Madrid Masters and finished second in the Dubai World Championship presented by: DP World a month later.
A loss of form and fitness then saw his progress curtailed but he finished fifth at the Qualifying School last year and showed he was close to being back to his best at Royal Johannesburg & Kensington Golf Club on Friday.
After firing a 67 on the tougher East Course on Thursday he went even better on the West, with two eagles and six birdies moving him to 14 under, three shots clear of nearest challengers Felipe Aguilar, Haydn Porteous and Anthony Wall.
The 33 year old opened with back-to-back birdies and picked up another shot on the seventh before giving it back on the eighth. He then birdied the ninth to turn in 33 and a further gain followed on the tenth.
An eagle then came on the par four 12th before a ten-foot birdie on the 14th and a second eagle of the day from 12 feet on the 15th opened up a sizeable gap.
He needed to show good skill and resolve to get up-and-down for par on the 17th and 18th and signed for an impressive nine under round.
Chilean Aguilar was blemish-free with birdies on the second, sixth, eighth, 11th, 15th and 17th in his 65 after joining McGowan with a 67 on the East Course in round one.
Wall finished in a share of second here last year behind Andy Sullivan and is once again in contention after an impressive finish on the East Course.
The Englishman began the day six under and made birdies on the first and fifth to turn in 35. He went bogey-birdie on the tenth and 11th and dropped another shot on the 14th but a brilliant curling putt for birdie on the 15th spurred him back to life.
That was followed by another birdie on the par three 16th and after putting his approach on the par five last to 12 feet, the 40 year old holed the eagle putt to sign for a 67.
Home favourite Porteous was playing the West Course and he turned in 34 with three birdies and a bogey. Further birdies on the tenth, 13th and 15th then fired him up the leaderboard and he bounced back from a bogey on the 17th with another gain on the last to sit three off the lead.
Welshman Stuart Manley was then at ten under after a 67 on the East highlighted by a chip-in on the 14th, alongside Swede Johan Carlsson who had five birdies and a bogey on the West.
Paul Dunne was playing in just his eighth professional tournament but the Irishman had eight birdies in a flawless 63 on the West to sit at nine under with Erik van Rooyen, who signed for a 64, and overnight leader Justin Walters who battled to a 69.
England's Richard Bland was also nine under after recording five birdies on his front nine on the East Course.
South Africans Jacques Blaauw and Zander Lombard were then at eight under with countryman Jean Hugo, who was three under at the turn after an eagle-birdie start.
Four-time Major Championship winner Ernie Els, playing in his first Joburg Open, faced an anxious wait in the afternoon after a second consecutive 70 got him to three under and left him in danger of missing the cut.