JOHANNESBURG - South African Tim Clark and Dane Morten Orum Madsen shared the lead after the Nelson Mandela Championship finally got underway on Saturday after rain delayed play for two days.
Amid news Mandela had been hospitalised for "medical attention", Clark and Madsen carded five-under-par 60s at the Royal Durban Golf Club, reduced from the initial par 70 to par-65 over 5,594 metres.
The rain-hit tournament was also reduced to 36 holes.
Just as the round was finishing, the presidency announced the country's first black president, now 94, had been hospitalised for "medical attention ... consistent with his age."
"There is no cause for alarm," said presidential spokesman Mac Maharaj in a statement.
The inaugural 1 million euro ($A1.25 million) tournament, named after the Noble Peace Laureate, was delayed two days after summer showers soaked the course this week.
Organisers have reduced the championship to a two-round competition, to finish by Sunday.
Clark, 36, shot six birdies and one bogey for his early lead before Madsen later caught up.