South African Charl Schwartzel has a second successive victory in his sights, four ahead of Northern Ireland's Darren Clarke, in the Joburg Open.
Schwartzel is currently 51st in the world and another victory would make it odds-on that he will earn a Masters debut at Augusta in April.
The top 50 the week before the event are guaranteed places in the opening major of the season.
Clarke is now outside the top 100 and has not been to The Masters since 2007, but the 40-year-old, whose 63 on the adjoining West Course on the first day was his lowest Tour round for 11 years, was impressive again in shooting 67.
He shared top spot after birdies on the fifth, sixth and eighth and, after three-putting the next, came home in 33.
A glorious third-round 64 took Schwartzel into the final day on 18 under par.
The 25-year-old won the Africa Open last Sunday with a 20-under total and the only time he has dropped a shot at Royal Johannesburg and Kensington this week was a double bogey at the 12th hole of his opening round on Thursday.
© Press Association