Tyrone Ferreira & Mark Murless share lead

South African Tyrone Ferreira showed no sign of nerves on his professional debut by firing a bogey-free, six-under-par 65 to share the lead after the first round of the Joburg Open on Thursday.

The co-sanctioned European and Sunshine Tour event at the par-71 Royal Johannesburg and Kensington Golf Club got underway in steady rain but that did not hamper Ferreira.

The 20-year-old, South Africa's number one amateur in 2007, birdied his second hole as a professional, a 490-metre par-five, to give his round immediate momentum.

"I hit a driver and three-wood to just short of the green and then chipped to two feet," said Ferreira. "That good start helped a lot for the rest of the day.

"It was a pretty awesome day. With all that rain, I thought level-par would be fine. But I hit the ball well, close to the flags, and then the putts started dropping," he told reporters.

Compatriot Mark Murless shared the lead with Ferreira, five straight birdies from the ninth hole moving him to the top of the leaderboard.

Hot prospect Ross McGowan, the 2006 English Amateur Champion, was in a tie for third one stroke back, alongside six-foot Welshman Sion Bebb and Spaniard Pablo Larrazabal.

McGowan said the unrelenting rain had made Thursday's first round a daunting challenge.

"It's not great out there, it's very tough and it's difficult to judge your shots, you've got to carry the ball a lot further," he told reporters.

"The fairways are very wet and there's not much run out there, maybe five or six yards, so I was trying to hit my drives higher."

McGowan bogeyed the first hole but that was the only blemish on a scorecard that included three birdies on the front nine and two coming in.

Bebb also did not drop a stroke but said it was definitely in spite of the conditions.

"I hate playing in the rain, to be honest. Once my grips get wet, I struggle. But it was sort of a strange day, not heavy rain but a continuous drizzle. I just hung on and the birdies came to me," Bebb said.

The tournament is being played on two coursesat the Royal Johannesburg and Kensington Golf Club and Murless, Ferreira, McGowan, Larrazabal and Bebb were all on the West Course.

Briton David Drysdale was the leading performer on the more daunting East Course where a four-under-par 67 left the Scot in a tie for sixth place.

Richard Sterne, the highest-ranked player in the field at number 44 in the world, shot a level-par 71 on the West Course, while Darren Clarke, world number 229 and aiming for a comeback, was in danger of missing the cut after a two-over-par 73.