The Springbok Sevens side were dealt a setback as they went down 24-14 to Australia in their final pool match of the HSBC World Championship in Valladolid in Spain on Saturday.
The result means that the Blitzboks will now have to face the winner of pool C, Spain, after they defeated Fiji.
The Australians, who were helped by former Wallaby coach Joe Schmidt ahead of the tournament, had a stellar second half to get them home.
Quewin Nortje had opened the scoring and put the Blitzboks ahead, only to see tries by Harry Wilson and Henry Hutchinson give Australia a 10-7 lead at the break.
Gino Cupido then edged the Blitzboks into the lead early in the second half, but a strong finish by Australia, which included tries for Ben Dowling and Josh Turner gave them the honours.
The Blitzboks' quarterfinal will be played at 5.11pm, with the semifinals and final scheduled for Sunday.
The Springbok Sevens side has won five tournaments in a row, adding the first World Championship tournament in Hong Kong to the four that took them to the HSBC World SVNS Series title before that.
In the Women’s section, Fiji pipped the Springbok Women's side 17-14 to leave South Africa without a win and facing Argentina in the ninth-place semifinal at 6.10pm.