Du Plessis called correctly for the third straight time in this series and elected to bat under clear skies. The skipper announced at the toss that Titans left-arm chinaman bowler Tabraiz Shamsi will make his debut here at the expense of orthodox spinner Keshav Maharaj.
"He's been extremely hard to pick with the pink ball, so we're hoping he'll be a real trump," Du Plessis said of Shamsi at the toss. "Just going on what we've seen facing him in the nets, he's been unbelievably hard to pick."
Meanwhile, Australia will field three debutants as they announced at the pre-match press conference.
Batsmen Matt Renshaw, Peter Handscomb and Nic Maddinson will all make their Test debuts, while fast bowler Jackson Bird and wicket-keeper Matthew Wade also returned to the side after a period of absence.
Joe Burns, Joe Mennie, Adam Voges, Peter Nevill and Callum Ferguson were the casualties from the Hobart disaster.
South African opener Stephen Cook enjoyed an early life in the third over of the match when Mitchell Starc trapped him plumb in front, but the big left-arm seamer had overstepped the front line and Cook was called back to resume his innings.
Australia: David Warner, Matt Renshaw, Usman Khawaja, Steven Smith (capt), Peter Handscomb, Nic Maddinson, Matthew Wade (wk), Mitchell Starc, Josh Hazlewood, Nathan Lyon, Jackson Bird.
South Africa: Stephen Cook, Dean Elgar, Hashim Amla, JP Duminy, Faf du Plessis (capt), Temba Bavuma, Quinton de Kock (wk), Vernon Philander, Kyle Abbott, Kagiso Rabada, Tabraiz Shamsi.
Independent MediaProteas captain Faf du Plessis has won the toss and elected to bat first in the third Test against Australia in Adelaide.
Original source: Faf chooses to bat first, debut for Shamsi