Chris Rattue: All Blacks' World Cup opponents still on the ropes after Newlands, but so is Sonny Bill

Sonny Bill Williams has hit the used-by date.

In the heat of the Newlands battle, the narrow defeat actually felt like a lift for South African rugby, while offering a glimmer of hope for the All Blacks' World Cup challengers.

In the cold light of day though, it was one of the great triumphs of Steve Hansen's reign, and more bad news for those aspiring to prise the Webb Ellis Cup away from New Zealand.

The All Blacks played badly and won, in a cauldron. Any other side, including England, would have succumbed if they had allowed that onslaught.

There were major lessons for Hansen: Sonny Bill Williams has hit the used-by date, Lima Sopoaga is probably a stop-gap No.10, and there is everything to gain by fast tracking Wellington's little Exocet Asafo Aumua as a World Cup hooker prospect.

It is hard to recall when the All Blacks faced such ball running fury compared to what Malcolm Marx, Eben Etzebeth, Steven Kitshoff and Pieter-Steph du Toit threw at them in Cape Town.

The Boks should have won that test. The All Blacks hardly responded with the ball, clung on defensively, and were essentially saved by moments of inspiration from three young outside backs - Damian McKenzie, David Havili and Rieko Ioane. They badly missed Brodie Retallick and Joe Moody. Yet they won, somehow.

Thanks to Marx and co. the Springbok pack was truly magnificent. But South Africa's outside backs are more likely to scare their own supporters than the opposition. Bryan Habana was an apparition.

Hansen, by his own admission, rolled the dice by throwing in five players who were underdone after being rested from the test in Argentina, and it showed. Sam Cane had a shocker by his best standards, Sopoaga plodded when he replaced Beauden Barrett.

Then there was SBW, who will be 34 by the time of the World Cup. He is already boxing on, his impressive frame leaning heavily on the ropes.

Hansen very likely knew all along that SBW was only an outside chance to last the 2019 distance, and has used him as a guard dog for the changing of the guard.

SBW best work is done it seems, he's already on old legs. There are very few flashes of his attacking genius, and there was little sting in defence against South Africa although his heart was in the game.

SBW is a true professional, although those infuriated by his cross-code antics don't see it that way. To be fair to his critics, all that code-hopping has left him devoid of rugby instincts, the ones which enable a Ryan Crotty to shine. Robbed of his physical prime, SBW's bare patches are showing through.

The All Blacks have amazing midfield prospects: Ngani Laumape, Anton Lienert-Brown, Jack Goodhue and even Jordie Barrett, who adds superior goalkicking. It's time to take one of those, to partner Crotty.

My pick would be Laumape, who offers Ma'a Nonu-class momentum on the fringes and has shown the odd nice touch. Most countries would be ecstatic with any one of those choices.

As for Aumoa, wow. Dare it be said, but he may be an even more dynamic runner than Keven Mealamu was when he first appeared on the NPC scene. And they didn't come any more dynamic than Little Kevvy.

Wellington is producing an amazing line in memorable hookers: Dane Coles, Ricky Riccitelli, Leni Apisai, Motu Matu'u...and now the extra special Aumoa. He's worth breaking my Mitre 10 Cup-watching ban for.

Coles, returning from concussion issues, is not back to his maverick best. The All Blacks will thrive by ensuring they have an x-factor hooker.

Number three, the injury ravaged Nathan Harris, is a mystery who is there by default. I can't remember him showing anything special on the test field, or even the Super Rugby field to be frank.

Hansen may not see it this way, but Coles and Codie Taylor have the job well covered, so up the ante.

Aumoa is a one man highlight reel. Time to move on, as it is with SBW.