Louis Oosthuizen reeled off six birdies in eight holes en route to a nine-under-par 62 that gave him the first-round lead at the South African Open.
The 2010 Open champion, playing in the competition for the first time in eight years, did not drop a shot on the Bushwillow Course and claimed a one-shot advantage over Madalitso Muthiya and Kurt Kitayama.
Zander Lombard finished two shots adrift of fellow South African Oosthuizen while Matt Wallace was one of three men to card a six-under 65.
Oosthuizen has just one victory on the European Tour since 2014 but the 36-year-old made half-a-dozen birdies between the 10th and 17th to reach the top of the leaderboard.
Most of those in the top 16 played the shorter but narrower Bushwillow Course, but on Friday Oosthuizen will have to tackle the Firethorn Course that the likes of Kitayama played on Thursday.
American Kitayama is hoping to continue his excellent form having won his maiden European Tour title at the Mauritius Open on Sunday.
Ernie Els, a five-time winner of the South African Open, was well placed after the first day at five under par.