The home contingent dominated the leaderboard during the early stages of day two of The BMW SA Open hosted by City of Ekurhuleni with Keith Horne joining overnight leader Jaco Van Zyl at the summit.
With play ending early on Thursday due to the threat of lightning at Glendower Golf Club, 33 players had to return to complete their rounds but none of them could make a dent in the upper echelons and Van Zyl kept hold of his one stroke lead at seven under.
With the leader going out in the afternoon, Horne took his chance to make a move and was one of eight South Africans in the top ten.
The 44 year old had been five under overnight and picked up shots on the 12th and 14th to join the leader after ten holes.
Jbe Kruger also shot a 67 in his first round and he was a shot behind the leaders alongside later starter Shaun Norris after two birdies and a bogey on his front nine.
Christiaan Bezuidenhout was making a move up the leaderboard and he was also in the group at six under after picking up four shots in 14 holes.
He birdied the 12th, 14th and 15th before giving one back on the next but a further birdie followed on the 17th. A brilliant chip-in from the bunker on the fifth then got him to within one of the lead in some style.
Two-time champion Retief Goosen and Justin Walters were then both a further shot back and one under for the day after 12 and 13 holes respectively.
Brandon Stone was also five under for the tournament and four under for the day after five birdies and a bogey in ten holes, alongside Ross McGowan, the highest featuring non-South African, who was one under through 12.
Defending champion Andy Sullivan shot a disappointing 75 on day one but was two under for the day through 11 holes as he battled to make the cut in his first European Tour title defence.
Richard McEvoy was level par for the week through 16 holes and he provided the highlight of the morning so far as he holed out from 159 yards with a nine iron on the 14th to register a hole in one.