AB de Villiers shapes as the riddle that Australia must solve as they seek to regain the ascendancy on the four-Test Qantas Tour of South Africa.
De Villiers has wound back the clock this series, posting his first century in more than three years to help deliver the Proteas a series-levelling victory in the second Test.
The gifted batsman has scored a total of 225 runs at 112.5 in the opening two Tests, making him the leading run-scorer in the series.
Alarmingly for Australia, de Villiers has been dismissed only once in each Test.
He was run out for a duck by David Warner in Durban, while he popped up a catch to Cameron Bancroft at short leg when the result was almost a formality in Port Elizabeth.
"I don't think we bowled as well to him as we could've," Australia coach Darren Lehmann said after the second Test.
"That's an area we can certainly improve on. We've got to bowl better to him, he's a class player.
"But in general I think our bowling was first-rate again, if we had the extra 100 runs it would've been a ripsnorter of a Test match."
The series continues in Cape Town next Thursday.
Australia skipper Steve Smith admitted de Villiers has looked "in complete control" throughout the current series.
"He's still human, so it is about getting the ball in the right areas enough times to him," Smith told radio station SEN.
"Which I think we haven't done so far throughout this series, and if we do that hopefully we can get his wicket nice and early and get the pressure on."
South Africa captain Faf du Plessis spoke of de Villiers' desperation to perform against Australia.
"I could see in his eyes that he had a huge hunger," du Plessis said.
"I said to him I'm just really pleased to see that he's walking the talk. All this stuff that he spoke about (performing against Australia) he's coming through with it.
"I'm really looking forward to see what he's going to do for the rest of the series. When he's in that sort of form, I'm very, very happy to have him in my side."
Qantas tour of South Africa
South Africa squad: Faf du Plessis (c), Hashim Amla, Temba Bavuma, Quinton de Kock, Theunis de Bruyn, AB de Villiers, Dean Elgar, Heinrich Klaasen, Keshav Maharaj, Aiden Markram, Morne Morkel, Wiaan Mulder, Lungi Ngidi, Vernon Philander, Kagiso Rabada.
Australia squad: Steve Smith (c), David Warner (vc), Cameron Bancroft, Pat Cummins, Peter Handscomb, Josh Hazlewood, Jon Holland, Usman Khawaja, Nathan Lyon, Mitchell Marsh, Shaun Marsh, Tim Paine, Jhye Richardson, Chadd Sayers, Mitchell Starc.
Warm-up match: Australia beat South Africa A by five wickets. Report, highlights
First Test Australia won by 118 runs. Scorecard
Second Test St George's Park, Port Elizabeth, March 9-13. Live coverage
Third Test Newlands, Cape Town, March 22-26. Live coverage
Fourth Test Wanderers, Johannesburg, March 30-April 3. Live coverage