The Blitzboks will face the USA in the quarter-finals of the Las Vegas Sevens after beating England 29-12 in their final pool game on Saturday.
South Africa started their campaign in Las Vegas by beating Japan 26-0 but then battled to a 5-5 draw with minnows Chile.
However, the Blitzboks saved their best performance for their final pool game, scoring five tries against England.
The South Africans started the game with aplomb as captain Philip Snyman took advantage of good work from Justin Geduld to open the scoring.
The Blitzboks were then made to work hard on defence and held Tom Bowen up to deny him a chance of dotting down over the line. However, the England man would not be denied twice and levelled the scores with a well-worked try.
Speedy wing Siviwe Soyizwapi showed how vital he is to the side, scoring a try just before half-time.
South Africa quickly took control of the second half as Geldud went over from close range to extend their lead, before JC Pretorius shook off two England defenders to score his first Sevens Series try.
England speedster Dan Norton then set up Charlton Kerr for what would be a consolation try, but the Blitzboks had the final say as Selvyn Davids sealed the victory with a final try.
Kick-off against the USA is scheduled for 4:10am (SA time) on Sunday.
— World Rugby Sevens (@WorldRugby7s) March 2, 2019