Both teams face each other after having recorded a big win and suffering a huge defeat respectively.
South Africa play their fifth super league game after chalking out an impressive 67-run win over the West Indies here on Tuesday.
Though they suffered a rude jolt prior to that, having lost to Bangladesh.
They have come back stronger and underlined their determination in no uncertain terms with their strong professional display against the hosts.
For New Zealand, a big defeat at the hands of Sri Lanka was nothing short of a huge shock. Having chalked out six wins in a row - including three in group stage, they were suddenly left looking vulnerable as their top order fell apart in the face of disciplined bowling from veterans Chaminda Vaas and Muttiah Muralitharan.
The Kiwi total of 220/9, built almost entirely around Scott Styris, proved entirely inadequate despite Shane Bond and Daniel Vettori turning in probing spells.
In the process New Zealand's frailties were exposed, and that too on a pitch holding no terrors for the batsmen.
Stephen Fleming fell early, the returning Ross Taylor aslo failed to disturb the scoreboard and had it not been for a 64-run eighth wicket partnership between Styris (111 not out) and James Franklin (25 not out), the Kiwis would not even have tallied 200 on the day.
Against the resurgent Proteas, it will be interesting to see whether New Zealand have that sort of resilience or not. It is more the ability of a team to bounce back and its will in question here.
The Black Caps are not a side to give up easily. Yet, at the same time it cannot be forgotten that in the World Cup, they have always promised more than they have eventually delivered. That is something they have travelled here determined to amend.
How deep that determination runs is now on test and this will make it an interesting game.
With eight points already in the bag, it is hardly time to press the panic button, but they will want to be in top form ahead of their final league game, against Australia here in eight days time.
The Proteas are still some way short of sealing their semi-final berth, but wins in their final two games will take care of that.
However, they are convinced that the team is peaking at just the right time. ''We are coming together very well. The Guyana result could have resulted in hasty reactions but none of that happened.
Instead, everyone was focused on doing his best against the West Indies on Tuesday, and that is an encouraging sign,'' said wicket-keeper Mark Boucher.
And with Shaun Pollock, Andre Nel and Kallis all in wicket-taking form, the Kiwis look like having their hands full in bouncing back from Thursday's setback. Most importantly, they need Shane Bond to fire. Every game they have won in this tournament has been after his early strikes.
Against the Lions he went wicketless, and the Kiwis lost.
It will be a face-off between two of the better all-rounders active in the game today. Kallis and Styris have both had good tournaments so far, and how they go on Saturday could also determine their team's fortunes.
South Africa: Graeme Smith,(Capt), Jacques Kallis, Loots Bosman, Mark Boucher (WK), AB de Villiers, Herschelle Gibbs, Andrew Hall, Justin Kemp, Charl Langeveldt, Andre Nel, Makhaya Ntini, Robin Peterson, Shaun Pollock, Ashwell Prince and Roger Telemachus. Coach: Mickey Arthur.
New Zealand : Stephen Fleming (capt), Peter Fulton, Ross Taylor, Scott Styris, Craig McMillan, Jacob Oram, Brendon McCullum (wk), Daniel Vettori, James Franklin, Shane Bond, Mark Gillespie, Jeetan Patel, Hamish Marshall, Chris Martn, Michael Mason. Coach: John Bracewell.
Umpires: Mark Benson (Eng), Daryl Harper (Aus) and Third umpire: Billy Doctrove (WI).
Match Referee: Chris Broad (Eng).