South Africa's Mark Murless eagled the 18th hole to take a one-stroke lead after the Joburg Open second round on Friday.
Murless hit his 230-yard three-wood to within five feet of the pin and sank his putt for a three at the last to card a three-under 68 on the tough East Course for a nine-under tally of 133 at Royal Johannesburg and Kensington Golf Club.
"What a way to finish," he told reporters. "It's a grind this week and if you get too excited this course will bite you back.
"Things were not going my way on the back nine but I kept to my game plan of hitting fairways and greens and keeping the ball in play."
Spain's Pablo Larrazabal shot a 68 to claim second place on 134.
The best rounds of the day, six-under 65s, came from South African Warren Abery and Britain's Darren Clarke, who flirted with the cut before picking up four birdies on the back nine to finish among a group of six players on 138.
Abery shared third position on 135 with fellow countrymen Charl Coetzee (67) and Tyrone Ferreira (70).
Clarke said a chat with television commentator and former European Tour player Ewen Murray had helped him.
"I did some work on the range with Ewen and I hit the ball really well and putted a lot better," said the Ryder Cup stalwart.
"Today was really good, especially my putting. Yesterday I was very poor and needed 33 putts. Today I had 29."
Clarke was also playing the East Course, one of two layouts used for the opening two rounds.