Australia set South Africa 421-run target

Matt Renshaw continued his prolific batting form before Australia declared on 314-6 at tea on the fourth day of the first Test on Monday, setting South Africa a daunting victory target of 421.

Australia held a 106-run first-innings lead after Renshaw scored 190, and the 30-year-old Queenslander again dominated the home bowlers at Kingsmead before a controversial caught-and-bowled dismissal by Keshav Maharaj ended his innings.

Renshaw looked disgusted after Maharaj appeared to juggle the catch before claiming it, with a television review confirming the dismissal.

Australia, who resumed on 33 without loss, scored 141 runs in a fast-moving morning session for the loss of four wickets and added another 140 in the afternoon as they sought to give themselves enough time to take the 10 wickets required for victory.

Opener Nic Maddinson, playing his first Test in a decade after scoring a duck in the first innings, struck 48 before being bowled by Anrich Nortje. Beau Webster remained unbeaten on 39, while captain Pat Cummins smashed four sixes in a whirlwind 32 off 12 balls.

Travis Head managed 11 and Marnus Labuschagne scored 37, but Labuschagne's 53-run partnership with Steve Smith, who made 27, helped Australia accelerate.

Smith was struck on the helmet by a Nortje bouncer while batting and underwent a lengthy on-field assessment before continuing his innings. He was later caught on the boundary off spinner Simon Harmer and did not take the field at the start of South Africa's second innings.

An Australian team spokesman said Smith was "undergoing further assessment", with an update expected later on Monday or on Tuesday. A concussion diagnosis could put him in doubt for the second Test in Gqeberha, which starts on Sunday.

South Africa were 60-1 at the time of filing, with Aiden Markram on 22 and David Bedingham unbeaten on 35. Josh Hazlewood dismissed Ryan Rickelton for two.

The hosts need a determined batting performance to avoid defeat and preserve captain Temba Bavuma's unbeaten record in 12 Tests as skipper.

Bad light curtailed play on each of the first three days and was again expected to threaten an early finish on Monday.