Home favourite Louis Oosthuizen wielded a red-hot putter to bag six birdies on his back nine and card an opening round 62 for a one-shot lead at the European Tour's South African Open on Thursday.
Oosthuizen's faultless round included nine birdies and he leads from Zambian Madalitso Muthiya and last weekend's winner at the Mauritius Open, American Kurt Kitayama, who both carded eight-under-par rounds of 63.
Oosthuizen and Muthiya played on the shorter Bushwillow Course at the Randpark Golf Club, which saw most of the low scoring on Thursday, while Kitayama teed off on the more formidable Firethorn Course to put himself into an excellent position.
Oosthuizen has never won his national Open championship before but is the highest-ranked player in this year's field and has some form after finishing in third place at the Nedbank Challenge last month.
Having turned at three under par, his superb approach to the 11th set up a second birdie in succession on the back nine, which turned into a hat-trick on the par-five 12th.
He managed further gains at 14, 16 and 17 for his lowest round on tour since the 2014 Alfred Dunhill Links Championship.
"My game's good, it's trending in the direction I want it to be," Oosthuizen told reporters earlier in the week.
"There's still a lot of work to be done to really be where I want it to be but I've been doing a lot of different things with my coach and just getting a feel for a few more things."
Muthiya had a contrasting round in which he landed five birdies in his first six holes, before slowing up on the back nine having turned in 29.
Kitayama also started with a birdie blitz in four of his first five holes and added an eagle on the par-five 14th, before finishing the 18th with another shot gained to tie for second.
The South African Open is the golf's second oldest national championship having first been played in 1893, and this year has been combined with the Joburg Open into one event.
The highest finishing three non-exempt players this week will gain exemption for the Open Championship at Royal Portrush next July, with 2010 Open winner Oosthuizen already on the entry list.