Australia strengthened their grip on the Durban Test against South Africa at the end of Day Four, needing just six wickets to take a 1-0 lead in the three-match ICC World Test Championship 2025-27 series.

South Africa were set a target of 421 and need another 319 runs to win.

Overnight, Aiden Markram and Wiaan Mulder were at the crease for South Africa.

While a successful chase looks highly improbable, if South Africa manage to reach the target, it would be a world record.

Highest successful run chases in Tests | Team | Score | Opponent | Year | | West Indies | 418/7 | Australia | 2003 | | South Africa | 414/4 | Australia | 2008 | | Australia | 404/3 | England | 1948 | | India | 406/4 | West Indies | 1976 | | West Indies | 395/7 | Bangladesh | 2021 | Resuming the day at 33/0 after bad light curtailed play on Day Three, Australia adopted an aggressive approach.

Travis Head was the first to depart, scoring 11 off 18 balls before mistiming a shot off Marco Jansen and handing Proteas captain Temba Bavuma a catch at mid-on, leaving Australia at 43/1.

Nic Maddinson then launched a counterattack, racing to 48 off just 38 deliveries, with six boundaries and two sixes.

However, just as he appeared poised to register his maiden Test half-century, Anrich Nortje breached his defence with a searing yorker, reducing Australia to 72/2.

Marnus Labuschagne and Steve Smith steadied Australia's innings, stitching together a fluent 53-run partnership to put the visitors in a commanding position.

Smith looked in good touch, striking three boundaries and launching Simon Harmer for a six.

However, he fell for 27 while attempting another big shot against the off-spinner, mistiming his stroke and picking out Marco Jansen....