Having sat atop the pile heading into this game, the consensus was that Australia would see off the below-par Proteas and thus secure their finish as group leaders, meaning they would face neighbours New Zealand - who finished fourth - in the semi-final.
However, led by a brilliant hundred from captain Faf du Plessis and an entertaining 95 from Rassie van der Dussen, they compiled a total of 325 in their 50 overs - a total that was ultimately too much for Australia.
Despite the best efforts of David Warner (122) and Alex Carey (85 off 69), they could never put themselves in a position to look like being able to chase down their target, which means they will now face old rivals England at Edgbaston on Thursday 11 July instead for a place in the final.
South Africa finally show batting capabilities
Coming out of a disappointing tournament, du Plessis would have been determined to ensure that his men fought hard to bow out with pride.
They certainly did so, with openers Quinton de Kock (52) and Aiden Markram (34) - deputising for the injured Hashim Amla - setting a solid platform for their middle- and lower-order to benefit from as they added 79 for the opening wicket.
Du Plessis then continued where the duo had left off, intertwining with the impressive van der Dussen to add 151 together as they managed to get on top of an Australian bowling attack that had previously wreaked havoc so far in the competition.
Top wicket-taker in the tournament Mitchell Starc (2-59) did not even complete his full quota of overs such was the pressure put on him by du Plessis and company, whilst fellow paceman Pat Cummins (1-66) also had one over left having been hit at over seven runs per over in his spell.
The 34-year-old then brought up the first three-figure score by any of his countrymen in the tournament, whilst his powerful partner holed out off the last ball of the innings to fall agonisingly short of a first 50-over century,
England awaits for below-par Australians
This sub-standard performance from Australia has had a huge say on how they may fare in the semi-final stage.
Had they won here then they would have lined up against their Trans-Tasman rivals - who are on a run of three consecutive defeats - on a Manchester wicket that looks to play to their strengths.
As it is they will now have to take on the hosts at Edgbaston - a ground they have not been successful at in any format, let alone one-day internationals, since 2001.
The Proteas managed to break through the strong top order that has served them so well, removing Aaron Finch (3) and Steve Smith (7) cheaply before then witnessing Usman Khawaja (18) hobble off with a hamstring injury when on only six.
They were, though, unable to remove the firstly obstinate and then swashbuckling Warner.
He survived a run-out scare after only the third ball of the innings, fortunate to benefit from a Kagiso Rabada throw that went to the wrong end - and never looked back from then.
When joined by the ever-improving Carey there was a chance of success, however, when Warner was removed thanks to a wonderful diving catch by Chris Morris at mid-on, their task looked severely more difficult.
Carey tried his utmost to keep the match alive, but when he chipped out to Markram at deep point in the 46th over with 51 still required from 28 balls their chances of victory were over.