MALELANE, 11 Dec 2014 (AFP) - The 26-year-old, who won all four of his European Tour titles in 2012, grabbed 10 birdies and no bogeys as he raced three clear of the field.
"I hit the ball superbly from the start to the finish,” said Grace, who almost holed his approach the 11th.
"I can’t remember the last time I hit 18 greens in a row, which is pretty nice, especially around this place where there are some daunting approaches. It’s a good feeling going into the rest of the tournament."
Fellow South African Jake Roos, playing his first event as a full European Tour Member, was in second place after a seven under 65, with last week’s winner Danny Willett and his fellow Englishman Matt Ford tied for third on six under.
Roos took the 15th and last place available on The Race to Dubai via last season’s Challenge Tour, while Ford was set to accept a job as a postman over the winter before he successfully negotiated November’s Qualifying School.
The 34 year old Roos began the day by holing a five iron for an eagle two at the tenth, and birdied the last to claim the clubhouse lead on seven under par.
"I felt comfortable and swung quite nicely," said Roos.
"I hit a lot of good shots and had a lot of short birdie putts on my front nine, and I was able to take advantage of a couple.
"When I holed that shot on my first hole it was an ice-breaker for me. It got me laughing and relaxed me, so it was a perfect start. It came out right on target and pitched a little short and went in."
Former Masters champion Charl Schwartzel, a three-time winner of this event and looking to become only the sixth European Tour player to win the same event three years running, carded a three under 69 which was matched by compatriot and fellow major champion Louis Oosthuizen.
Leading scores on Thursday in the first round of the Alfred Dunhill Championship at the par-72 Leopard Creek Country Club:-
62 - Branden Grace (RSA)
65 - Jake Roos (RSA)
66 - Matt Ford (ENG), Danny Willett (ENG)
67 - Tjaart Van der Walt (RSA), Michael Hollick (RSA), Ignacio Elvira (ESP)
68 - Carlos Del Moral (ESP), Lucas Bjerregaard (DEN), PH McIntyre (RSA), Kevin Stone (RSA), Shaun Norris (RSA), Jbe Kruger (RSA), Benjamin Hébert (FRA), Peter Lawrie (IRL), Francesco Molinari (ITA), Chris Swanepoel (RSA), Craig Lee (SCO), Scott Jamieson (SCO), Magnus Carlsson (SWE)
69 - Stuart Manley (WAL), Jason Barnes (ENG), Andrew Johnston (ENG), Charl Schwartzel (RSA), JJ Senekal (RSA), Julien Quesne (FRA), Louis Oosthuizen (RSA), Louis De Jager (RSA), Christiaan Basson (RSA), Jean Hugo (RSA), Soren Hansen (DEN), Adilson Da Silva (BRA)
70 - Morten Madsen (DEN), Borja Virto (ESP), Eduardo De La Riva (ESP), Pedro Oriol (ESP), Wallie Coetsee (RSA), Danie Van Tonder (RSA), Desvonde Botes (RSA), Jaco Ahlers (RSA), George Coetzee (RSA), Ulrich Van den Berg (RSA), Dylan Frittelli (RSA), Lyle Rowe (RSA), Daniel Brooks (ENG), Chris Paisley (ENG), Jason Palmer (ENG), Niclas Fasth (SWE), Kristoffer Broberg (SWE), Johan Carlsson (SWE), Espen Kofstad (NOR), John Hahn (USA)