Kagiso Rabada tore through Australia in another spell of furious fast-bowling on Monday to put South Africa level in the series in what could be his final act of the series.
The 22-year-old fast bowler took his match total to 11 wickets with 6-54 in Australia's second innings, opening the fourth day by blasting out Mitchell Marsh's off stump in the first over to set up South Africa's six-wicket win at St. George's Park.
Yet Rabada could go from main attraction and man of the match in Port Elizabeth to no show for the final two tests of a tense series in Cape Town and Johannesburg because of two disciplinary charges against him for aggressive celebrations of Australian wickets.
Rabada had his first disciplinary hearing for bumping into Australia captain Steve Smith after getting him out in the first innings on Sunday night after the day's play. He attended a second hearing on Monday for screaming in the face of opener David Warner in the second innings.
The first charge for the shoulder bump on Smith is likely to earn Rabada a two test ban on its own. The International Cricket Council is still to release its decision.
"It's not looking good," Rabada said of his participation in the rest of the series. "I've let myself down and let the team down." He called his performance in the second test "bittersweet."
Rabada took the first three wickets of the fourth day to hurry the Australians out for 239 and another batting failure in their second innings.
South Africa clinched its win by chasing down the meager target of 101 before tea on the fourth day. It wasn't straightforward, with Australia removing Hashim Amla and AB de Villiers in quick succession to have the South Africans 81-4.
South Africa skipper Faf du Plessis took control to see his team home with Theunis de Bruyn.
The South African victory stops Australia's momentum from a win in the first test in Durban and gives the home team a chance of a first home series win over the Aussies since 1970.
"That's an incredible test match for us. Especially after what was a tough loss in Durban," du Plessis said.
Australia has been dominant in South Africa since the end of apartheid, winning five series and drawing its other two.
But, not for the first time, the tables turned dramatically in a series between the two closely match teams.