The Spaniard has won twice before at Gary Player Country Club before this event joined the European Tour International Schedule and his eight under par total was his lowest round in Sun City since he claimed his first title in 2001.
It was also his lowest opening round of the season by two shots and left him four clear of fellow Masters Tournament winner Charl Schwartzel, Finn Mikko Korhonen and Frenchman Mike Lorenzo-Vera.
That gap matched the largest of the season after 18 holes, recorded by Arjun Atwal at the AfrAsia Bank Mauritius Open almost 12 months ago.
There was then a group of six players at three under including 2010 Open Championship winner Louis Oosthuizen.
Since being selected as a Captain's Pick for the Ryder Cup by Thomas Bjørn, Garcia has had a top ten at the Portugal Masters, won three points at Le Golf National to become Europe's all-time leading scorer and won the Andalucia Valderrama Masters hosted by his own foundation.
The 38 year old is now going in search of a second win in a row and a first Rolex Series victory in South Africa.
"It felt great,” he said. “I rolled the ball nicely, I made some good putts here and there.
“It was one of those rounds where things happened nicely to me. I think I played very smart, I probably wasn't swinging unbelievably but I kept it under control and kept the ball in play all the time which is difficult to do here.
“I managed to guess some of the winds here right and that is very, very difficult. When you can do that here, it's nice to be able to shoot a score like this."
Garcia holed a 12-foot right-to-lefter on the first and an 18-footer on the seventh, with a monster putt on the ninth helping him turn in 33 and share the lead.
He had a good look at eagle on the par-five tenth but had to settle for a birdie before he holed from the fringe on the 11th to hit the front on his own.
An approach to six feet on the 15th moved him two ahead and he kept his foot down, putting his tee-shot to five feet on the par-three 16th and then holing a 20-foot left-to-righter on the penultimate hole.
Playing partner Schwartzel birdied the par-five second and par-three seventh but gave the shot straight back on the next to turn in 35. The home favourite then picked up shots on the tenth, 15th and last.
Lorenzo-Vera was in the first group of the day off the tenth and he made birdies on the 13th, second, sixth and ninth.
Korhonen had birdies on the second, sixth and tenth to go with a bogey on the ninth before sensationally chipping in for birdies on the 12th and last.
Frenchman Benjamin Hebert, Australian Jason Scrivener, English pair Andy Sullivan and Matt Wallace, and China's Wu Ashun were at three under alongside home favourite Oosthuizen.
The South African made five birdies and two bogeys as did Scrivener, Sullivan and Wallace, with the latter coming home in 31. Wu was bogey-free in his 69, with Hebert dropping a single shot on his closing hole.
Defending champion Branden Grace and New Zealander Ryan Fox were two under, with Race to Dubai hopefuls Li Haotong and Rory McIlroy a further one and two shots back respectively.