Aphibarnrat played the first five holes in three-under-par, with four birdies and a bogey, while those hoping for a first South African winner of the Nedbank Golf Challenge since Trevor Immelman in 2007, will be heartened by George Coetzee’s start, the debutant claiming birdies on the first three holes to take a share of the lead.
The opening holes of the European Tour event held few worries for the golfers as Joost Luiten, Dawie van der Walt, Stephen Gallacher and Danny Willett were all on two-under-par.
Van der Walt, in the field by virtue of winning the 2013 Sunshine Tour Order of Merit, made the fastest start of all by birdieing the first hole and then chipping in for eagle on the 520m par-five second, but could not pick up any more shots on the next three holes, dropping a stroke on the par-three fourth after finding the greenside bunker and then leaving his chip way past the hole.
Thomas Bjorn, the defending champion, started where he left off last year in his brilliant final-round 65, by birdieing the first hole.
South African Tim Clark, who teed off in the first group, set the early pace with birdies at the first two holes, but he then lost his way with a bogey at the fifth and a double-bogey at the tricky par-four eighth.
Aphibarnrat, a Sun City rookie, showed that he had all the information he needed on the Gary Player Country Club course as he started birdie-birdie, but Coetzee stayed in contact thanks to some precision iron play.
The conditions at Sun City were close to perfect, a slight breeze helping to offset the heat, and the golfers took advantage with a dozen already under par as the first group reached the turn.