Rain in South Africa delayed the start of the tournament for two days, but the layoff didn't seem to affect Clark and Madsen, who both shot 60 Saturday and led Lindai Ndwandwe and Chris Lloyd by one shot.
The wet weather prompted tournament officials to shorten four holes to par 3s and lower par for the course from 70 to 65. As a result, the leaders were 5-under for the tournament.
Clark shot birdie 2 on three consecutive holes on the back nine. Madsen had two bogeys on his first four holes but got hot and carded seven birdies the rest of the way.