Trevor Fisher Jnr made five birdies in a row to catapult himself to the top of the leaderboard early on day one of the BMW SA Open hosted by City of Ekurhuleni, but World Number Two Rory McIlroy was hot on his heels.
The South African has finished in the top 15 in each of his last five appearances at this event and he made seven birdies in his first 11 holes to get to six under, two clear of McIlroy and Brett Rumford.
Both the Australian and the home favourite narrowly missed out on keeping their playing privileges last season and they set the early pace before McIlroy went on an impressive run of his own.
Starting on the back nine, Rumford birdied the tenth and an eagle on the par five 15th was followed by another gain on the 16th to leave him out in front on his own.
Fisher Jnr's start was not so impressive as he bogeyed the 11th but after back-to-back birdies on the 12th and 13th he came to life, making five in a row from the 15th to open up a two-shot lead.
McIlroy is playing this event for the first time since the 2009 season when he narrowly missed out on a play-off spot but was making himself very much at home in his debut at Glendower Golf Club.
After four opening pars, the Northern Irishman put his approach to the par three 14th close to set up a first birdie of the day and he rattled off two more before a 20-footer on the 17th left him just two off the lead after nine holes.
Englishman Daniel Brooks flew out of the blocks with an eagle on the second and a birdie on the fifth to sit at three under alongside South Africa's James Kamte, who had three birdies in his first 11 holes.
There was then a group of eight players four shots off the lead.
