Australia extended their lead over South Africa to 280 runs but lost four wickets in reaching 174-4 at lunch on the fourth day of the first Test in Durban on Monday.
Matt Renshaw was unbeaten on 32 and Alex Carey on 5 at the break.
Australia, who led by 106 runs after the first innings, resumed on 33-0 and pushed the scoring along to set South Africa a big target.
Travis Head was the first to go for 11, chipping a rising delivery from Marco Jansen straight to Temba Bavuma at mid-on.
Nic Maddinson, who made a duck in the first innings on his Test return after a decade away, was bowled by Anrich Nortje for 48.
Steve Smith was caught on the boundary for 27 off spinner Simon Harmer, and Marnus Labuschagne fell for 37 when he miscued Keshav Maharaj to Bavuma in the covers.
Bad light has cut short play on each of the first three days. Australia will look to push their lead past 350 before declaring, giving themselves time to bowl at South Africa’s top order before the close.
Australia made 390 in their first innings, including 190 from Renshaw, before bowling South Africa out for 284.
The second Test of the three-match series starts in Gqeberha on Sunday.

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