New Zealand captain Richie McCaw hailed an outstanding defensive effort by his side as they retained the Bledisloe Cup with a hard-fought 20-10 victory over Australia at AMI Stadium in Christchurch.

The win was the ninth in a row for the All Blacks over their trans-Tasman rivals, and it moves them within a solitary point of securing another Tri Nations title.

They were given their sternest test of the season to date by the Wallabies, who were able to prevent their hosts from enjoying the amount of quick front-foot ball they had used to such deadly effect in their first three Tri Nations fixtures.

But that still wasn't enough for Robbie Deans' side as tries from in-form full-back Mils Muliaina and centre Conrad Smith, plus 10 points from the boot of Dan Carter, saw the All Blacks home.

Australia picked up a try thanks to a solo effort from Kurtley Beale, with Matt Giteau adding the conversion and a penalty.

‘Some big hits went in but the boys played defensively for each other and the boys are pretty happy with that,’ said McCaw.

‘Such hard defensive games take their toll and the players' tanks were fairly empty with 10 minutes to go, but we felt we started to get on top of them physically [towards the end].’

Graham Henry's men will now get the chance to wrap up the Tri Nations when they travel to face South Africa at Soccer City in Johannesburg in two weeks' time, but McCaw is taking nothing for granted.

‘It's going to be a big challenge to win in Johannesburg but one that we will get excited about,’ said the openside flanker.

One area of concern for New Zealand will be their performance of their line-out, which stumbled notably at times having shown a massive improvement in recent weeks.

But forwards coach Steve Hansen is confident of sorting out any glitches by the time they meet the Springboks for the third time this campaign.

‘The things that didn't quite go as well we can fix pretty quickly,’ said the former Wales boss.

Deans, meanwhile, was left to rue the fact that his side failed to put away the few clear chances they managed to create.

The Wallabies struggled to break down the black wall in front of them, but they had a glimmer of hope when wing Drew Mitchell made a great jinking break, only for a lack of accuracy to stop the move in its tracks.

Deans, who was coaching on his old stomping ground today having guided the Crusaders to five Super Rugby titles before joining Australia, said: ‘If you aspire to beat the All Blacks you have to play your hand when it presents itself.'