Their 26-0 victory over Australia completed the whitewash of their group after their 45-0 rout of Kenya and their 33-0 defeat of Canada earlier in the day.
Series defending champions New Zealand, standings leader Fiji and Samoa also went unbeaten on day one of the South Africa rugby sevens to canter into the Cup quarterfinals.
The host also won all three of its pool games Friday in the third leg of the world series.
New Zealand overpowered Morocco 39-7 to open its Pool B campaign. It then routed Scotland 45-0 and finished by beating France 41-0 to set up a quarterfinal against Australia.
Fiji cruised past Portugal and Zimbabwe and came from 14-0 down against Wales to win its last Pool D match 29-14. Gold Coast opening leg winner Fiji plays last week's Dubai winner England in Saturday's quarters.
Samoa beat England 24-14 in the decisive Pool A match.
Tries: Cecil Afrika, Mark Richards x 2, Chris Hunt
Conversions: Cecil Afrika, Branco du Preez, Mark Richards
Blitzboks’ fixtures, day one:
South Africa 33 Canada 0
South Africa 45 Kenya 0
South Africa 26 Australia 0
Full Results:
Pool A
England 26, United States 7
Samoa 17, Argentina 5
Samoa 24, England 14
United States 21, Argentina 14
Samoa 14, United States 12
England 19, Argentina 0
Pool B
France 31, Scotland 7
New Zealand 39, Morocco 7
France 19, Morocco 7
New Zealand 45, Scotland 0
Scotland 50, Morocco 0
New Zealand 41, France 0
Pool C
South Africa 33, Canada 0
Australia 31, Kenya 14
South Africa 45, Kenya 0
Australia 33, Canada 10
Canada 26, Kenya 5
South Africa 26, Australia 0
Pool D
Fiji 31, Portugal 7
Wales 42, Zimbabwe 7
Fiji 42, Zimbabwe 17
Wales 34, Portugal 7
Portugal 24, Zimbabwe 12
Fiji 29, Wales 14