Pat Cummins produced a brilliant spell towards the fag end of a curtailed fourth day at the Sydney Cricket Ground to keep Australia in the hunt for a 3-0 series sweep. After declaring on their overnight score of 475/4 which left Usman Khawaja stranded five shy of a double century, the hosts, led by their captain who snapped up 3 for 29, had South Africa in a spot of bother at 149 for 6. The Proteas will now face a fight on the final day to avoid defeat.