Dominant at scrum time, physical in the collisions, not afraid to back himself with the ball in hand.

The veteran of 72 Test matches and the ACT Brumbies' all-time games record holder watched in awe as Tupou ran through South Africa like a freight train and threw flick passes even Quade Cooper would be envious of.

Tupou was immense as the Wallabies rose to No. 3 in the world rankings following a 30-17 win over the Springboks - their second in as many weeks - in Brisbane on Saturday night.

"You see a lot of it with the big boys, once they realise they're so much bigger, stronger and more powerful than everyone else, they become unstoppable," Alexander said.

MORE RUGBY UNION

"Especially now he feels at home, he looks like he feels at home out there, just look to him to continue to keep imposing his will on the game.

"Every involvement he has, he just shifts momentum towards Australia. Every time he touches the ball, every involvement he has, he wrestles a bit of momentum Australia's way

"He's doing all the hard work really well, lineout lifting, scrumming, cleaning out, he's doing all the basics well. On top of laying the foundation he can do a bit of the flashy stuff which is hard.

"In the past you've got grafters and then you've got flashy players who might shirk some of the harder stuff. To see him and Allan [Alaalatoa] really do the hard work and do it well, and Taniela with a bit of flair on top of that, it's super impressive."

Tupou put in a stirring 78-minute shift for the Wallabies in the absence of Alaalatoa, who left camp last Monday to return to Canberra for the birth of his child.

Whether Wallabies coach Dave Rennie should start Tupou or Alaalatoa has often been the subject of debate, but Alexander sees a simple solution.

"We're just so lucky having him and Allan Alaalatoa, they're the two best tightheads in the world in my opinion," Alexander said.

"We're just so lucky to have both of them, to rotate them and keep them both fresh and performing. It's awesome for Australian rugby.

"It's a hard slog in there at tighthead. A big part of why Taniela played so well is he has had limited minutes so far, Allan has played a fair bit so Taniela is still fresh. They should keep rotating through and keep sharing the load."

Alexander says one thing is certain: this Wallabies outfit can give fans hope on the road to the 2023 World Cup.

He rattles off names like Tupou, Alaalatoa, Marika Koroibete, Samu Kerevi, Quade Cooper, Michael Hooper, and Nic White: "genuine gamebreakers at a world level" that will have Australia buzzing.

Rennie hopes the Wallabies are giving Australian rugby fans something to be proud of. His South African counterpart Jacques Nienaber, in contrast, was left apologising to Springboks fans for what he said was their worst performance since 2018.

"Sorry, that's all we can say. This is not a performance I would say was worthy enough for a Springbok jersey," Nienabar said.

"Everything [went wrong]. We were truly beaten in every department, hands down beaten in everything.

"It's something we'll have to figure out quickly. There's no positives, but it's nice to play against our SANZAAR partners again; you get tested differently and it's a big eye opener."

The Springboks now face the All Blacks, who will provide another assessment of where the South Africans are at. World Cup winners in 2019, they missed last year's Rugby Championship.

The South Africans have lost their place at the top of the world rankings. While the Wallabies rose to No. 3, the All Blacks have reclaimed the mantle as the world best.

Unbeaten tournament favourites New Zealand, featuring a staggering 11 changes to the starting XV, beat Argentina 36-13.

"I'm just glad we got the win," captain Ardie Savea said.

"We knew they'd be tough, but I'm proud of the boys and as the week went this week you didn't really notice all the changes. Spending quarantine together has really tightened the group and ... we expect them to come out and perform."

AT A GLANCE

The Rugby Championship: WALLABIES 30 (Len Ikitau 2, Marika Koroibete 2 tries; Quade Cooper 2 conversions; Cooper 2 penalties) bt SPRINGBOKS 17 (Lukhanyo Am try; Handre Pollard 4 penalties) at Lang Park.

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