South Africa's 231-run win is their second-largest victory margin (in terms of runs) against Australia since their readmission to international cricket. The only bigger win was in Perth in 2012, when they won by 309 runs. Overall, it's their fifth-largest victory against Australia.
Out of 19 Tests between South Africa and Australia in South Africa since 1992, only one has been drawn. The last 16 Tests here have all produced decisive results.
The passage of play that turned the game around was the outstanding spell of fast bowling immediately after tea when Australia slipped from 141 for 1 to 166 for 6. After a fantastic opening partnership, Australia's Nos. 3-7 scored a total of 7 runs: Alex Doolan made 5, Michael Clarke and Brad Haddin a run each, while Shaun Marsh and Steven Smith were dismissed for first-ball ducks. It's the second-lowest aggregate for the No. 3-7 batsmen from any team in a Test. The lowest was also by Australia against South Africa, in Cape Town in 2011, when they made 5; Clarke and Haddin were the two from the current line-up who were also in that middle order - Clarke made 2 and Haddin 0. (Mitchell Johnson batted at No. 7 in that game, but came in at No. 8 here.) The top three lowest ones are all by Australia - they had also made 7 against England in 1902.
The nine batsmen following the openers scored a total of 22, the second-lowest for Australia in a Test innings, following the 13 they scored against England at Edgbaston in 1902. On that occasion, the highest score by one of those nine batsmen was 5; here, it was 6, by Mitchell Johnson and Ryan Harris.
The difference in the South African attack was largely the amount of reverse-swing Dale Steyn obtained with the older ball, and it showed in the problems he caused Australia's batsmen. Till the 37th over of the Australia innings, the batsmen had a control factor of 84% against Steyn. After tea, the control factor dropped to 66%.
Doolan and Marsh, the heroes of Centurion, flopped in both innings at St George's Park, scoring a total of 13 runs in fours innings between them. In Australia's Test history, only four times has their Nos. 3 and 4 scored fewer runs over four innings in a Test - the last time they made fewer than 13 was more than 100 years ago, in 1902, when they managed 12. In 1899 at Headingley, Monty Noble and Syd Gregory, Australia's Nos. 3 and 4, both bagged pairs, the only such instance in Australia's Test history.
Australia's spectacular collapse after their superb opening stand was reminiscent of Chester-le-Street in 2013, in the fourth Test of the Ashes. Then, chasing a fourth-innings target of 299, Australia got off to a fine start too, with Chris Rogers and David Warner adding 109, before the middle order crumbled (though not as dramatically as they did here). No other batsman touched 25, and Australia were bowled out for 224. Overall, there have been only 11 instances of Australian openers putting together 100 or more in the fourth innings of a Test, and Warner-Rogers is the only pair to achieve this feat twice. The 126 they added is also the first instance of an opening-wicket century stand in the fourth innings of a Test in Port Elizabeth.
Amid all the wickets going down at the other end, Rogers held firm and scored a courageous and resilient 107. It was the 15th instance of an Australian opener scoring a fourth-innings century, and a second one for him: he'd made 116 against England in Melbourne last year, helping Australia chase down a target of 231 quite easily. Rogers is one of only three Australian opener to achieve this feat twice: Mark Taylor and Arthur Morris are the other two.
Warner had another good Test, scoring 66 in the second innings to follow on the 70 in the first, thus also continuing his superb run in the second innings of Tests. In his last ten Tests, Warner averages only 25.90 in the first innings, with two 50s, and a highest of 70; in the second innings, his average shoots up to 73.88, with three centuries and three fifties in ten innings.
If Warner had a good Test, Marsh certainly didn't. He followed up his first Test scores of 148 and 44 with a pair in the second, which means he has scored six ducks in 15 innings. He has also been out for 3 twice, while the remaining seven innings have fetched 487 runs.
Apart from Steyn, the one South African player whose return to form would have pleased them was Hashim Amla: after scoring 105 runs in seven innings since his previous hundred - including a duck in the first innings here - Amla scored an unbeaten 127. It's the 18th instance of a South African batsman scoring a duck and a century in the same Test; the last such instance was also in a Test against Australia, in Adelaide in 2012, when Graeme Smith scored 122 and 0 in the Test made famous by Faf du Plessis' stubborn fourth-innings 110 not out on debut.