Despite losing the final to Argentina in Hamilton last weekend, New Zealand moved to the head of the points table, while South Africa, who had shared the lead with Samoa, had to settle for fifth after losing their quarterfinal with France 17-22. They were beaten by Ireland 14-21 in the playoff for fifth place.
They are to meet New Zealand in the last game of their pool at 5.49 pm (NZT) on Saturday.
New Zealand's first game against Uruguay is at 5.28 pm on Friday. After that, they play Kenya at 12.06 pm on Saturday.
Blitzboks captain Siviwe Soyizwapi said the side held a brutal post-mortem after their Hamilton performance, and he was confident they would respond in Sydney.
"We can look each other in the eye again after that, as everybody owned up when we did that post-tournament analysis.
"The players had to take it on the chin; it was clear in the reviews that we neglected the system and that the mistakes we made were of our own doing."
They accepted guidance from their coaches about what needed to be done better.
"The reality is our coaches have been there before and they know what they are talking about when a regroup is needed," he said.
Critics have criticised the lack of size in the side, but Soyizwapi said that was nothing unusual; they had always struggled for size.
"Some of the so-called smaller players represented this team to great heights in the past and the ones here will be no different. It is the size of your head that counts, and we have to show that this weekend."
Soyizwapi, who has scored 139 tries in 232 sevens series games, has been transitioning to play in the forwards. That results in him having less time on the field, but he will revert to the wing for the Sydney tournament.
Moving into the forwards was something he needed to get used to, he said.
"Whatever the team on the field looks like, they need to represent the badge and express the culture of the squad.
"We need to show that from the first match against Kenya and sustain that until the last game we play."
The Black Ferns, who also top the points table, open their tournament against Papua New Guinea at 3.06 pm and France at 9.05 pm on Friday. They play Japan at 3.12 pm on Saturday.
Catch the action live on Sky Sport NZ.