LUKE Charteris has demanded that Wales maintain their high standards in defence in their World Cup quarter-final as they aim for a hat-trick of clean sheets against southern hemisphere superpowers.

Wales return to Twickenham to lock horns with South Africa after being beaten 15-6 by Australia in the Pool A decider.

It was a bruising encounter in which they paid the price for failing to score when enjoying a two-man advantage in the second half but they did prevent a classy Wallabies side from crossing their whitewash.

They managed the same against South Africa last autumn when winning 12-6 at the Millennium Stadium and will attempt to repeat the trick against a Boks side that scored 23 times when winning Pool B.

"When you look back whenever we have a big win, our defence has usually been a massive part of that," said former Newport Gwent Dragons lock Charteris.

"That was the pleasing thing from the Australia game – our defence was really good to hold out that Australia team to no tries.

"In the autumn that was a big feature and we also got confidence from the game in South Africa (in the summer of 2014). The second Test we put in a good performance and should have won that apart from the last few seconds of the game."

Wales will have to cope with a resurgent South Africa who have fought back from their opening shock at the hands of Japan.

They have kept things simple and been direct with their imposing pack but Charteris believes Wales have had a good tune-up for the confrontation.

"You have to give Australia credit, their pack has come on massively in the last 18 months," he said.

"That was a very tough test up front for us and we came through that one at least with some parity.

"We will probably need to raise it against the South Africans. They have got very good young second rows and then they have Victor Matfield at the other end of the spectrum, but still one of the world's best."

Boss Warren Gatland still has some selection calls to make up front with Dan Lydiate highly likely to return at blindside and Gethin Jenkins set to share the duties with loosehead Paul James.

However, behind he is down to the bare bones following Liam Williams' foot injury and the three-quarters will be wrapped in cotton wool this week.

"Unfortunately, we are getting quite used to injuries now, particularly losing our backs," said Charteris.

"Every time that has happened someone has come in and they have done an awesome job. I have no doubt whoever steps in on the weekend will raise their game to those levels."