Darren Clarke bounced back from his difficult opening round to shoot a solid three-under-par 69 and move to two under at the Alfred Dunhill Championship in Malelane.
However, a strong finish gave South African Omar Sandys the outright lead at the end of day two.
The 30-year-old Free Stater was one under par through nine holes, but managed two birdies in his last four holes to match his opening round 68 and move to eight under par for the tournament, two ahead of the field.
His biggest challenge came from Englishman Lee Slattery, who carded the best round of the day with a 65 and an overall total of 138 for six under par.
Home favourite Ernie Els leads a group of six players on five under, including Britons Richard Bland, John Bickerton, Craig Lee and overnight leader Sion Bebb as well as South African Titch Moore, who shot a 68.
Ross Fisher, currently second on the European Order of Merit, managed to fight back from his poor 76 on the opening day by shooting a 70.
The only big name to miss out on the weekend action was 2004 winner Charl Schwartzel after a four-over-par 43 added to his 75 from Thursday.
Darren Clarke bounced back from his difficult opening round to shoot a solid three-under-par 69 and move to two under at the Alfred Dunhill Championship in Malelane.
But it was the rather jovial Sandys who claimed the honour of topping the leaderboard after two days at the Leopard Creek Country Club.
Coming from a rather humble background that has seen him struggle with endorsements and sponsorships for large parts of his professional career, he admitted that believing in his ability was crucial to his position at the end of the day.
He said: "It feels good to be here you know. It's all about guts and just trusting yourself."
So good was his performance, that Sandys could have had an even better score with an eagle chance coming on the 18th after a brave approach to the green.
He said: "Everyone wanted me to make that putt. On my side, I just wanted to two-putt.
"Not because of the scores that were following me or where I'm lying on the leaderboard, but for my round, I was planning and I've always been planning to shoot four good rounds in a row.
"And 68 is my handicap at home. So I'm actually happy to shoot it at Leopard Creek twice."