The Springboks got off to a solid start in the London Sevens on Saturday when they thrashed Canada and Russia.
Paul Treu’s team, who won the Paris Sevens title last week, are the defending champions of the London leg, having beaten England in the 2005 final.
South Africa scored six tries and conceded one in the dying seconds of both their 34-7 defeat of Canada and 38-7 victory over Russia.
In other Pool C matches, a four-try haul from Santiago Gomez Cora gave Argentina a 24-10 victory over Canada in their second game to ensure they too are unbeaten after two games, having earlier accounted for Russia by a similar margin, 26-10.
In Pool A, Fiji moved closer to claiming the IRB Sevens title with Lepani Nabuliwaqa scoring two tries in their 38-5 defeat of Italy to go with his double against Portugal (33-14).
France also remain unbeaten after two games, but only thanks to a brace of tries in the final minutes of their encounters with Italy (20-5) and Portugal (22-10), the latter having led their more fancied opponents 10-7 at half-time.
In Pool B, England remain unbeaten after a convincing 51-0 victory over Twickenham debutants Germany.
Kenya meanwhile produced the first upset with a deserved 26-7 victory over Australia. Tries by Dennis Mwanja, Sidney Ashioya, Humphrey Kayange and Felix Clement Ochieng kept alive their qualification hopes and earned them a standing ovation.
In Pool D, Rudi Wulf scored a hat-trick for New Zealand in their 59-0 defeat of Tunisia. Alfred Pelenise sat out this game, having scored five tries in their opening 34-7 victory over Scotland.
Samoa now await the New Zealanders after the Paris Sevens finalists overcame Scotland 22-5, Timoteo Iosua taking his tally to four tries for the tournament with another double, having also touched down in their 38-7 defeat of Tunisia.
Day 1 results so far:
Fiji 33 Portugal 14
France 20 Italy 5
South Africa 34 Canada 7
Argentina 26 Russia 10
New Zealand 34 Scotland 7
Samoa 38 Tunisia 7
England 26 Kenya 0
Australia 40 Germany 12
Fiji 38 Italy 5
France 22 Portugal 10
South Africa 38 Russia 7
Argentina 24 Canada 10
New Zealand 59 Tunisia 0
Samoa 22 Scotland 5
England 51 Germany 0
Kenya 26 Australia 7