What is it about Australia that brings out the best in JP Duminy?
Duminy on Saturday posted the fifth Test century of his career - and third against Australia - to help South Africa take complete control of the first Test.
The left-hander now boasts a Test batting average of 66.33 in Australia, after producing a polished innings at the WACA before being dismissed for 141 on Saturday.
That mark is in sharp contrast to his overall Test average of 34.22.
Duminy, who hadn't scored a Test ton since 2014 prior to his fluent dig in Perth, has often frustrated South African fans in a 37-Test career.
The 32-year-old has failed to deliver under pressure in the past, especially at home where he averages 27.60.
But his best is very good, as Steve Smith and his colleagues witnessed on Saturday.
"I think you kind of know you have to bring your A-game when you play against them," Duminy replied when asked about his knack of producing his best against Australia.
"There's no period in the game when you get to rest, and today is a testament to that.
"I didn't feel at any stage I could relax and take my time. I was just making sure I was focused every ball."
As Dean Elgar dug in early, Duminy kept the scoreboard ticking over with a couple of textbook cover drives.
Peter Siddle didn't need a reminder of his talent, having played in the game when Duminy set the bar high on Test debut at the same ground in 2008.
Duminy finished 50 not out in Perth eight years ago when the tourists completed a record run-chase at 4-414. He then scored 166 in the following match at the MCG.
Duminy reached three figures in a tick under four hours at the WACA on Saturday, with his impressive knock following Test hundreds against Australia in Port Elizabeth (2014) and at the MCG (2008).
