Du Plessis' telling off, and Johnson's bouncer

South Africa have never beaten Australia in a series at home since readmission. Australia are looking to test their progress away from their own backyard. The stakes involved in the Cape Town Test were never more clear than on the third day.

The look in one's eyes when they are trying to coerce a reaction out of an opponent. The way that person bristles as they try not to give them that satisfaction. The gestures and words that have nothing to do with the score but everything to with the atmosphere. The way one team gets under another's skin and wears them down.

That is what today was all about.

Faf du Plessis had survived being cut in half by Ryan Harris off the first ball he faced, which he does not think he nicked despite Australia's half-appeal and the small smudge on Hotspot. He was beaten by the same bowler and edged one which didn't reach the cordon and then it happened. It was the 34th over, Mitchell Johnson bowled a short one, which hit du Plessis on the pad and rolled toward the stumps. Du Plessis dared to pick up the ball and though Australia did not appeal, they did snarl.

"They were pretty aggressive about it," du Plessis said. "I thought I was being a nice guy by passing it back but they are like a pack of dogs when you get near that ball. Whatever. That's the way they play their cricket and I can see they don't like it."

Du Plessis admitted he was not 100% sure of the laws of touching the ball and when he was informed he could be putting himself in danger, took it to heart. "I won't do it again," he said.

Which is exactly what Australia want. Although Johnson would not reveal exactly what he said, because he couldn't remember, he admitted du Plessis was given a talking to. "A lot of the boys just said it's not time for him to be fielding," Johnson said. "I was going to let the ball hit me but he didn't throw it straight. Hads is a big believer in that he always wants to pick the ball up. That's our job, we're there to field. We should be doing it."

What they may really have been about was maintaining the ball themselves in order to achieve reverse swing which introduces the next layer of the day's competition.

Australia had the ball reversing shortly after the first hour and du Plessis admitted to being pretty surprised. "I was really surprised to see the ball reverse from their side. It was 20 overs old and with the damp conditions... let's just leave it at that," he said.

After David Warner suggested South Africa may have used dubious methods to achieve the same in Port Elizabeth, du Plessis made sure to tread carefully but left it out there anyway. Johnson was more pragmatic about Australia's art and explained how he thought they achieved it. "It was our plan coming here to get the ball to reverse and bowling second helped," he said. "The wicket was abrasive enough to bowl cross seam and I usually hit the same so I could hit it nice and rough and we can get that shine off the ball. We're not surprised that it went."

Reverse swing is going to be important for Australia because the more they get, the less time they will feel they need to bowl South Africa out.

This is the trickiest balance to achieve and it will be up to Michael Clarke to see if he can get it right this time. Memories of Adelaide 2012 will be fresh in his mind. South Africa's target was 430 and he gave himself four sessions to bowl them out. South Africa survived and du Plessis, who was their hero then, has reason to believe they can do it again.

"It's always tricky with third innings. You don't know what's a good total to set. If you bat for too long, you take time out of the game and if you don't bat enough, the opposition could chase it down," he said. "We've been good in fourth innings recently, whether chasing it down and getting close. At the moment a draw, we will look good but you never know."

Johnson did not play in that match but he knows exactly what du Plessis is talking about. "We want to get a few more runs on the board. That wicket is starting to play a few tricks; going up and down. It's an Adelaide-type wicket," he said. "We've played there, they've played there and they did a good job keeping us out last time. Maybe five sessions would be nice. But it depends how many runs we get."

In their attempts to win this match, Australia will turn on the aggression and South Africa will expect more of what they saw from Johnson today when he felled Steyn to set off some ...

Steyn, perhaps unknowingly, lit the flare when he issued the challenge, walked out to bat despite his hamstring strain and galloped down the stairs at a fair clip. He was asking for trouble when he cut and drove Shane Watson for two boundaries and meted out the same treatment to Harris. After he got away with an edge off Johnson, the Australian quick had to respond. He dished up a bouncer which Steyn could not avoid and struck him flush on the badge.

"I know that I am going to get it back," Johnson admitted. "He is a fierce competitor. He just smiled straight away."

Some of those grins will be in jest and some of them will have a little more needle behind them. None of them will be recorded on the scorecards and only a few will make it on to highlights. They're the moments that make memories and that's where we'll keep them.