SUN CITY, South Africa – Louis Oosthuizen overcame an uncomfortable bout of kidney stones to shoot a bogey-free 63 and take a three-shot lead after the first round of the Nedbank Golf Challenge in South Africa on Thursday.

Oosthuizen nearly withdrew and said he was up since 3 a.m. local time on the morning of the first round in some discomfort.

He didn't show it on the course apart from having to walk a little slower round Gary Player Country Club.

The South African carded four birdies on the opening nine and five on the closing stretch to go 9 under and take a big lead at a tournament he's never won.

Thomas Detry is second on 6 under, Guido Migliozzi third on 5 under, and defending champion Lee Westwood and Ernie Els part of a tie for fourth another shot back.