Third Test, SCG, Australia v NZ, day three, SCG

First innings: Australia 454, New Zealand 3-141, at lunch

Taylor 21, Phillips 3

Australia has carved through the New Zealand top order before lunch on day four of the Third Test at the SCG.

The early destroyer was Nathan Lyon, with two wickets indicating the spinner will have a big role to play as the pitch deteriorates.

Lyon first had Tom Blundell bowled through his legs for 34, then had an ill Jeet Raval out lbw after he'd held up an end for 31 valuable runs.

Immediately after the DRS review confirmed Raval was out, Mitchell Starc has Tom Latham out for 49 when the opener spooned a catch to Pat Cummins off the bowling of Mitchell Starc.

New Zealand's batsmen had resumed their first innings run chase on 0-63 with Tom Latham on 26 and Blundell on 34.

The tourists are chasing Australia's 454, but working against injury and illness within their camp as a flu-like virus continues to take a toll on the team.

It was revealed on Saturday that the players stopped high-fiving a sick teammate to prevent a virus spreading, as coaching staff prepared to field in case of emergency during another dramatic day at the SCG.

Recalled batsman Raval joined the ever-growing sick bay, while scans revealed pace bowler Matt Henry had broken his thumb.

Raval, who has not been in great form, came the crease after Blundell fell.

Henry has bowled through the pain barrier after trying stop a Joe Burns drive on day one because the blow affected his non-bowling hand.

However, the handy tailender may not bat if Australia continue to dominate a one-sided three-match series.

Raval was the latest Kiwi to succumb to a flu-like virus, joining skipper Kane Williamson, batsman Henry Nicholls and spinner Mitchell Santner who were all ruled out before Friday's toss.

Raval was resting in the dressing room when the Black Caps took to the field on Saturday and missed the first hour of play.

He was feeling healthier by stumps on Saturday, but worryingly the bug has so far affected players for days rather than hours.

"You have to be very diligent with things like hand sanitiser and being around food and people who aren't feeling great," New Zealand spinner Todd Astle said.

"You have to have certain measures in place. We've been smart about it and in terms of high-fives it was different with Jeet – (it was tap) elbows or just a gesture.

"We don't want anyone else going down."

Australia has been set up in the game by Marnus Labuschagne's 215, with his insatiable desire for runs able to be be traced back to three months before he became Steve Smith's concussion replacement at Lord's.

The star of the third Test in Sydney, Labuschagne's summer of big scores has netted him 837 runs – the most of any Australian in a five-Test home summer.

Three months before his Ashes call up his golden run began with Glamorgan, where he became the first player to reach 1000 runs in the 2019 County season.

Labuschagne averaged just 31.95 in first-class cricket when he arrived in Wales last April. But his record since is unmatched.

In the nine months that have followed he has hit 2627 first-class runs at an average of 69.13, having also played more days of elite cricket than any other player last year.

"There is no better way to learn your game than playing games," Labuschagne said.

"I had the opportunity to do that in England. And score hundreds and get

I had the opportunity to do that in England. And score hundreds and get consistent over there. It was something I hadn't been able to do in Shield cricket."

consistent over there. It was something I hadn't been able to do in Shield cricket."

Small changes in Labuschagne's technique have been credited to his English stint, including straightening his bat path.

Third Test: Lyon and Starc cut through NZ bats_1
Inset: Marnus Labuschagne in full flight at the SCG on Saturday. Photo: AAP 

In 18 innings Labuschagne hit five centuries for Glamorgan, with his highest a 182 against Sussex in late May.

But it was also from that innings in Hove the 25-year-old learned perhaps his biggest lesson of 2019.

Labuschagne was chastised by Glamorgan coach Matthew Maynard for leaving runs on the field and not turning his hundreds into doubles.

So when he got his opportunity at the SCG on Saturday, after three times falling between 140 and 190 this summer, he wasn't going to let it go.

"He (Maynard) has sent me a few messages when I threw away a couple of my opportunities to get a double," Labuschagne said.

"He said that to me a few times, one day he said 'there's only a few times in your life that you can make a triple and you threw it away today, well done.

"I was like: 'That's a bit stiff'. But he's been great.

"Even those small things, as a player sometimes you don't realise that in the moment.

"Because in the moment, you are playing, especially on a high score you are playing with a bit more freedom instead of realising the opportunity you do have."

-with AAP