Ireland's Damien McGrane fired an eight under par 63 to claim the clubhouse lead in the first round of the Joburg Open before thunderstorms halted play.
McGrane carded five birdies in a flawless front nine 31 on Royal Johannesburg and Kensington's West Course, where low scoring was the order of the day.
The 40 year old, whose only European Tour title came at the Volvo China Open four years ago, then collected two further birdies and chipped in for an eagle on the 15th.
The only blemish on his scorecard came at the 18th with a bogey five, but he still enjoyed a one shot advantage over South African Desvonde Botes.
Botes carded a seven under 65 to claim outright second, and was the only player in the top 17 to make his score on the par-72 East Course.
“I am delighted to be in a good position after round one,” said McGrane. “For the last three or four years Irish golf has been quite incredible, and I think we feed off each other. For a small nation it sure is great to be there or thereabouts.
“I stacked up a few birdies during the round, but that eagle really turned my round.
“I played beautifully from start to finish, and this course does give up opportunities. The greens and weather were perfect, so if you’re on your game there are birdie chances. Needless to say you have to make the chances and today I holed a few nice putts.
“I hit plenty of fairways and holed a few nice putts for birdie, it was just the bogey at the last which was disappointing. Apart from that it was a perfect round of golf.”
No fewer than seven players were a shot further back on six under – with six of those in the clubhouse.
Scotland’s David Drysdale holed a 20 foot birdie putt at the last for an inward nine of 30, while his compatriot George Murray reached the same mark when he holed a ten foot birdie putt at the par three 16th.
They were joined by George Coetzee, the home favourite spectacularly chipping in at the last, as well as another South African in Shaun Norris, Spain’s Carlos Del Moral and Sweden’s Joel Sjöholm.
England's Jamie Elson, returning to the European Tour after holing a 40 foot birdie putt on the final hole at Qualifying School to gain his card, was also on six under after 15 holes.
Masters Tournament champion Charl Schwartzel, looking for a third straight win in the event, was among the later starters and was one over par after nine holes.
If the South African makes it a hat-trick he would become one of only six players, alongside Ian Woosnam, Sir Nick Faldo, Colin Montgomerie, Ernie Els and Tiger Woods, to win the same European Tour event three years in a row.