Australia makes it to stumps at 1-45 and and trail by 144 after one day at the MCG.
David Warner has looked solid at the crease, and Marnus Labuschagne will resume alongside him tomorrow.
Warner is after a big score in his 100th Test match.
The star of the day is young all-rounder Cameron Green, who took his first 5-for in Test cricket.
Green cleaned up the tail after another disappointing South Africa innings.
The Proteas were 1-52 and then lost three quick wickets before lunch, leaving the tourists scrambling.
Hopefully this match lasts longer than two days.