South Africa have conceded they will spend day four in Durban trying to contain Australia, after Pat Cummins' men put themselves in a commanding position.
Australia will resume on Monday at 0-33, with a 139-run lead and appearing the only team with any realistic chance of winning the first of three Tests.
The biggest barrier could still be Durban's early sunsets and afternoon cloud cover, with bad light ending each day early and Australia needing enough time to win the match.
