Australia coach Michael Cheika says his team can improve again for next week’s Rugby World Cup final against New Zealand after scoring four tries to beat Argentina 29-15 at Twickenham.

Asked about the first final between the trans-Tasman rivals, Cheika said his side genuinely had not thought ahead of the clash with Argentina but now had to get better “against a pretty dynamic team”.

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“We had to work hard to stop them scoring a try so I’m really happy with our defence,” Cheika said.

“We gave away too many penalties in the first half but tried to rectify that in the second.

“Overall, I’m happy we scored four tries, I think we can improve again, and that’s important.”

Captain Stephen Moore was not surprised by how much defence the Wallabies had to do against the Pumas, who are renowned for chancing their arm in attack.

Despite how often Argentina’s speedy outside backs threatened, Australia’s vaunted defence continued to turn up.

“That took a fair bit out of the tank. We know the task next week is huge and we’ll have to play really well,” Moore said.

Winger Adam Ashley-Cooper was the star man with a hat-trick of tries but also credited his side’s defence as key.

“We knew they would play from everywhere in the field and they did that tonight,” he said.

“Our defence was huge right across the park. The defensive line was really strong.”

Australia’s brilliant back rower, David Pocock, showed the signs of battle with blood all over his face from the early exchanges.

“It was incredibly tough – as we knew it would be,” he said.

“Credit to Argentina, it was physical, but both teams looked to use the ball and both teams were working hard until the 80th minute.

“I thought there were a few pieces of finishing from our back line which was the difference, but it was tough.”