This was Aiden Markram's fourth Test century — second of the series.
Nathan Lyon removed Dean Elgar for 19 (47) after South Africa chose to bat versus Australia at Johannesburg.
"I am ultimately responsible for the culture of the team and I've been thinking about my position for a while" - Darren Lehmann.
Despite his sympathy for Steven Smith, South Africa skipper Faf du Plessis is determined to seal the ongoing four-Test series versus Australia at home.
Cricket Australia, today, banned Steven Smith, David Warner for one year, and Cameron Bancroft for nine months following ball-tampering saga.
"I'm not going to sit here and say that we're whiter than white or anything but we'll try and play the game within the rules" - Ottis Gibson.
"I'm pretty sure that it was going on during Ashes. But it wasn't the reason why England lost 4-0. They still would have lost that series." - Michael Vaughan.
Nathan Lyon is overall the 33rd bowler to 300 scalps, sixth Australian, second spinner and the first offie from his country to the feat.
Earlier, Australia folded for 255 and conceded a vital 56-run lead to South Africa in the morning session.
Cameron Bancroft was questioned by umpires during the 43rd over of South Africa’s second innings after appearing to have an object in his hand while fielding at covers.