The Blitzboks remain unbeaten in Dubai after defeating Great Britain in their Pool A encounter at the Sevens Stadium on Friday.
South Africa won 21-7, after leading 14-7 at half-time.
As it happened | Dubai Sevens - 2nd leg
The South Africans ran three tries through Zain Davids, Shilton van Wyk and Ronald Brown with Branco Du Preez and Brown adding the conversions.
Meanwhile, the British replied with a sole try through Alex Davis with Robbie Fergusson converting the try.
The win sees the Springboks Sevens win their 20th consecutive World Rugby Sevens Series match.
Earlier on Friday, the Blitzboks cruised to victories in their Pool A games over Japan (48-0) and Ireland (21-12).
In Saturday's Cup quarter-finals, the South Africans will face Kenya at 08:50 SA time.
Blitzbok coach Neil Powell said afterwards that although his side played well on attack, they somehow could not get into their full stride.
"Maybe that was due to our form of last weekend, with the teams coming out to throw everything at you," said Powell.
"I think we really worked hard on our defensive system, although there are still some room for improvement."
Regarding Saturday's quarter-final against Kenya in the knockout stages, Powell said: "An African derby will always be a physical one, so we have to make sure we make our tackles - we will have to make those one-on-ones stick."
The Blitzboks won last weekend's first Dubai Sevens event after a 42-7 win over the USA in the Cup final and are the favourites to triumph once again this weekend.
South Africa 21
Tries: Zain Davids, Shilton van Wyk, Ronald Brown
Conversions: Branco Du Preez (2), Brown
Great Britain 7
Try: Alex Davis
Conversion: Robbie Fergusson
?? A bit scrappy at times and properly tested, but the Blitzboks are still unbeaten at the @Dubai7s courtesy of a 21-7 win over @GBRugbySevens in their final pool clash. #BestofUs #HSBC7s @ASICS_ZA @FNBSA pic.twitter.com/NlFGzLBwOy— Springbok Sevens (@Blitzboks) December 3, 2021