Branden Grace set the early pace at the Joburg Open after a blistering eight-under-par 63 in the opening round.
The South African recorded six birdies and an eagle on the West Course at the par-71 Royal Johannesburg and Kensington Golf Club – a start that enabled him to sit two clear of compatriot James Kamte.
Welshman Jamie Donaldson also had a productive day as he shot six birdies against two bogeys for a 66, sitting alongside Sweden’s Alexander Noren.
Paul Waring from England and Dutchman Floris de Vries were five under through 15 and 12 holes respectively.
Ireland's Colm Moriarty and Scotsman David Drysdale were in the clubhouse on four under after going around in 67 at the last of the four co-sanctioned European and Sunshine Tour events in South Africa.
Northern Ireland's Darren Clarke finished on one under while compatriot Gareth Maybin completed the course in two under.
Stuart Manley from Wales and Sweden’s Joakim Haeggman were four under at the halfway point of their rounds while local quartet Theunis Spangenberg (12), PH McIntyre (nine), Andre Cruse (nine) and Shaun Norris (six) were on the same mark.
Richard Sterne, the 2008 champion, was a further shot back after a round of three-under 68, while last year’s winner Charl Schwartzel was on level par through three holes and Northern Ireland’s Darren Clarke was one over at the same stage.
They will have to work hard to emulate leader Grace, who went out in 32 on the front nine and followed that with an even better 31.
This week’s event is being played over two courses on the first two days – the rounds are divided between the East and West courses, before the cut is made and the final two rounds are played on what many believe is an easier East course.
Grace played the West today and was thrilled with his effort, saying: “I thought beforehand that one of the keys was to go low on the West and fortunately I managed to do it today.
“I played really well, I didn’t make any mistakes out there and everything went to plan, so I’m pretty pleased with that.”