Home favourites dominated the leaderboard on day two of the BMW SA Open as Andy Sullivan faced an anxious wait to see if his title defence was over.
Sullivan, whose victory at Glendower 12 months ago was one of three in 2015, had struggled to an opening 75 on Thursday, which included four-putting the 17th.
And the world number 34 could only add a 72 in Friday's second round to remain three over par, two shots outside the current predicted cut.
Starting from the 10th, Sullivan had got back to level par thanks to birdies on the 10th, 12th and 16th, only to double bogey the 17th for the second day in succession.
A birdie at the second repaired some of the damage but was followed by another double bogey on the third and meant the 29-year-old former supermarket shelf-stacker was left hoping for a repeat of Thursday's weather, when a blustery wind made scoring difficult for the later starters.
At the other end of the leaderboard, nine of the top 12 players were South African, with Keith Horne setting the early clubhouse target on eight under after adding a 69 to his opening 67.
Jbe Kruger was a shot behind following a 70, alongside overnight leader Jaco Van Zyl, who was among the later starters and had opened his round with a par on the first.
England's Ross McGowan was the best-placed non South African, the world number 317 sharing fourth place on six under after three birdies and one bogey in a round of 70.