Josh Inglis completed a spectacular return after posting his second Test century as Australia stretched their first-innings lead to 82 runs despite the best efforts of South Africa offspinner Simon Harmer on the third morning of the series-deciding Test.

Australia reached lunch in a strong position and will still be hopeful of building their total on a benign Newlands surface, with allrounder Cooper Connolly on 20 not out.

No. 5 Inglis hit 102 off 135 balls and shared a fifth-wicket partnership of 185 with Alex Carey, who made 80. Both batters were dismissed by Harmer, who continued to be South Africa's most potent bowler and he's returned figures of 4 for 104 off 37 overs.

Inglis made the most of his opportunity after replacing an injured Steven Smith, ruled out with a neck injury sustained in the second Test. Having long been on the fringes, Inglis had not played Test cricket since December and wasn't considered for selection in the opening two matches due to a finger injury.

Playing his first red-ball match since March in the Sheffield Shield, Inglis started scratchily before superbly shifting gears as his innate aggression eventually came to the fore. His knock added to the ton he made on Test debut against Sri Lanka in early 2025.

Australia started the day's play at 330 for 4 with a lead of one run as they eyed a big first innings lead. South Africa badly needed early wickets with the second new ball, but Inglis and Carey were untroubled.

Kagiso Rabada had to wait to bowl after spending some time off the field on day two due to stomach cramps.

The burden fell on Marco Jansen, who was comfortably South Africa's best seamer on day two. But he couldn't get his tail up like he memorably did to remove Cameron Green and Matt Renshaw in quick succession earlier in the innings.

Jansen's struggles were evident when he bowled a beamer to Carey, who ducked safely out of the way. The bowlers were not helped by sloppy fielding with Inglis entering the nineties after Gerald Coetzee misfielded at mid-on to continue his tough return to Test cricket.

Rabada entered the attack 30 minutes into the day's play, hoping improved health might spur a better performance after going wicketless on day two. He was left frustrated after producing an edge off Carey only for Harmer to drop a catch low to his left at slip.

Harmer's woes were compounded by his finger being split open although, fortunately, not on his bowling hand. Having bandaged the wound, Harmer was deployed into the attack only to be reverse swept brilliantly by Inglis, who reached his century in style.

But Harmer finally ended the partnership by catching the outside edge of Inglis, who coincidentally fell for the exact same score as his only previous Test century. Harmer did his best to rally South Africa, snaring Carey with a tossed up delivery that was well caught low down by Aiden Markram at slip.

As has been the trend in this series, wickets fell in clumps. Australia's collapse of 10 for 3 was complete when Rabada had Pat Cummins lbw for a duck in a decision that was upheld on DRS, with ball-tracking returning umpire's call.

South Africa hoped to wrap up the lower-order quickly but Mitchell Starc provided resistance and supported Connolly as Australia passed 400. Coetzee, playing his first Test since November 2024, had some belated cheer after a wayward bowling effort when he nicked off Starc for 11.