Charl Schwartzel produced a stunning burst of scoring to extend his lead to four shots midway through the final round at the Tshwane Open.
Schwartzel, who is looking to win an eighth European Tour title on home soil, began the day on nine under par, one shot ahead of countryman Zander Lombard.
The 31 year old moved to ten under when he rolled in his birdie putt from 15 feet at the second but dropped a shot at the next.
Schwartzel bounced back with consecutive birdies at the sixth and seventh before rolling in his tricky eagle putt from ten feet at the ninth to reach the turn in 31.
That eagle saw the 2011 Masters Champion move to 13 under par, four shots clear of nearest challenger Lombard, who mixed three birdies with two bogeys on his front nine.
Dean Burmester was a further stroke back after he recovered from an early bogey to notch five birdies in his next seven holes and move to eight under at the turn.