Image source, Getty Images

That was another fascinating session in this Test and series.

Replying to South Africa's 329 yesterday, Australia started well as Travis Head and Matt Renshaw shared an opening stand of 58.

Head, in particular, was aggressive and was helped out by some loose bowling.

But the Test swung again when off-spinner Simon Harmer bowled Travis Head with his first ball of the day. Head chopped onto his stumps yet again.

And Harmer removed under-pressure Australia number three Marnus Labuschagne in the very same over. Labuschagne was out for a duck, extending his run of innings without a Test century to 48 - a record for an Australia top-order batter.

After that it was all about Matt Renshaw and Cameron Green surviving until lunch. They did so, leaving the score 90-2, and play will resume around 11:10 GMT with the Test in the balance.

Ha, that's some way to go into the lunch break!

Cam Green steps down the pitch and hammers Marco Jansen over mid-off for four. That's a contender for the shot of the morning - a bit of a statement from Green, maybe.

Another gripping session in this series decider.

Marco Jansen is back for what could be the final over before lunch.

Hello!

Looks like Coetzee has been brought back to unsettle Cam Green with the short ball and he's done it well, whacking Green on the glove as he is completely squared up and rushed for pace.

Coetzee wastes it though, firing the last ball of the over down the leg side for four byes.

Simon Harmer is taken out of the attack for Gerald Coetzee, which is an unusual move. It could just be that he's going to change ends - we'll see.

Temba Bavuma brings Marco Jansen back for a spell before lunch.

He and Kagiso Rabada were a little expensive with the new ball but he's immediately into a good rhythm here, a bit more confidence behind him now that South Africa have a couple of wickets.

Jason Gillespie
Former Australia bowler on ABC

That will never be broken. I say that because, respectfully, I don’t think anyone will be given that length of time again.

In getting out for a duck today, Marnus Labuschagne has broken the record for most innings without a century as a top four batter in Australia's Test team.

He previously shared the record of Alec Bannerman, who played his last Test in 1893.

Labuschagne now stands alone on 48 innings.

South Africa have kept Matt Renshaw very quiet since Travis Head got out. He drives a little riskily at Harmer for a couple, and wicketkeeper Ryan Rickelton's frustration is picked up on the stump mic.

It's tense.

Cameron Green relieves the pressure with a couple of boundaries.

The first is streaky, flying off the outside edge from a loose drive, but the second is a lovely cover drive that'll give him a bit of confidence after a nervy start.

Simon Harmer continues to twirl away. He's settled in to this spell beautifully, which is very good news for Temba Bavuma.

He can plug the spinner in at one end, and rotate his quicks from the other. Quick burst of Jansen or Rabada before lunch, perhaps?

Edged... but short of slip!

Things are bubbling away out there. Green definitely looks twitchy and South Africa sense it. He's faced 10 balls and is yet to get off the mark.

Four runs and two wickets from the last five overs. South Africa have surged back.

Image source, Getty Images

Simon Harmer has Cameron Green in his sights now, playing his first game of the series. He just about survives a maiden.

No pressure...

A maiden from Wiaan Mulder.

Simon Harmer's over has turned this on its head (sorry, Travis).

South Africa were all over Marnus Labuschagne there, sensing his vulnerability, and it worked brilliantly. They're buzzing now.

Echoes of yesterday's day, though South Africa's openers dominated for longer.

Eeek.

Labuschagne nudges the ball nervously into the leg side and it drops just short of the fielder at short mid-wicket.

Plenty of chatter from the South Africans all of a sudden!

Now then, Marnus Labuschagne...