There's just something about Australia that gets Faf du Plessis' back up. His first Test ton came against them in a declaration of determination. His first ODI century was against them too, an announcement of aggression.

Now du Plessis has moved past the introductions with a second one-day hundred against the team considered the most confrontational around, and it is this innings that will secure him his preferred position for the foreseeable future. "It was one of the best hundreds I've seen in a long time," AB de Villiers, South Africa's captain, said. "I am very proud of Faf. He has cemented that No.3 spot."

One-drop is a soft spot for South Africa because for the better part of the last two decades it has belonged to Jacques Kallis or - when Kallis was see-sawing between availability and unavailability - to a place-holder. Colin Ingram was one, JP Duminy another, and du Plessis the third, though he was always the one most likely regarded as the crown prince should the king ever need permanent replacing.

Du Plessis successfully took over Kallis' position in Tests and has now started doing the same in ODIs. He is able to step into the giant shoes not because he is more talented than the other candidates but because he has a better understanding of the role.

Like Kallis, du Plessis' job is to provide stability. "My job is to score hundreds, so I tick that box," he said. But unlike Kallis, who often performed rescue jobs for South Africa but seldom won 50-over games later in his career, du Plessis sees his job as being to see South Africa through. "But when you score a hundred, getting a team across the line is always sweeter."

This time he was not able to do that because he lacked support. Du Plessis acknowledged a middle-order meltdown left him stranded and he did not feel in control. "Even though we were going well and I was scoring the runs, it was a little too far away with us losing wickets all the time. I never felt quite close enough to get us over the line," he said. "That was the difference with the previous game. We had a good partnership there - myself and AB. Forty and 30-run partnerships are not going to win you the game."

Neither is bleeding 60 runs in five-over bursts, and when asked to identify where South Africa lost the match, du Plessis said it was more with the ball than the bat. "If we have to pinpoint where we lost the game, it's probably in Mitchell Marsh's innings," he said. "We probably took our foot off the gas to Marsh and he demolished us and that's the difference between winning and losing. In that period, we weren't on the money."

Even after Marsh had proved stroke-making did not have be stuttering, no South African batsman besides du Plessis played fluently and he believed conditions had something to do with that. "The way the wickets play here is a big reason for that. The ball gets slower so it's difficult when you come in as a new batter to score runs because they bring the field up and it's tricky to get singles. Once you push them out, it becomes easier."

When du Plessis gets the balance between attack and defence right, like Kallis, getting into his head or under his skin is difficult, and he seems to be in such a place now. "I am batting nicely but definitely not on top of my game. I can improve a lot," he said. "What's really important is that when you are in some sort of form you need to make sure you get big runs, because it can change very quickly and then 30 runs seems a long way away, so I need to make sure I keep putting in big runs for this team."

That may serve as a warning for Australia, after Marsh said seeing du Plessis step on his stumps was, "probably the only way we were going to get him out," and that he had played a "special innings."

For du Plessis, the method of dismissal was not as amusing as it was disappointing. "It was ridiculous. It's not nice when you are hitting the ball nicely like that. I knew I had to do something to get us across the line but you learn from these things," du Plessis said. "Next time I will make sure I am not as deep in the crease."

Next time Australia know they will be in for another fight.