YOKOHAMA, 21 Sep - After hearing all the talk that he could be residing over a team on the wane, coach Steve Hansen had demanded a performance to shut out "all the noise" and this victory, New Zealand's 15th straight World Cup win, offered the perfect deafening response from the champions.

It was not easy. Of course, it never promised to be as they launched their bid for a third consecutive World Cup against a powerful South African side that began on a charge and never rolled over in what was described perfectly by winning captain Kieran Read as "one heck of a test match".

The South Africans kept coming, inspired in the second half by the mesmerising running of Cheslin Kolbe, even after the All Blacks had demonstrated their majesty, hitting them with a swift one-two punch in the space of three first-half minutes with dazzling tries from George Bridge and Scott Barrett.

Yet even though the difference in the attacking quality of both teams was fairly glaring and even allowing for the fact they gave away nine penalties to the All Blacks' four, South Africa were still able to reduce their 17-3 half-time deficit to just four with a thundering second-half fightback, which at times saw some helter-skelter attacking and countering that simply took the breath away.

The resistance was led by a try from the indefatigable Pieter-Steph du Toit, when the All Blacks defence fell asleep at a ruck, and a drop goal from Handre Pollard, but the champions, inspired by flanker Ardie Savea’s magnificent performance and the sheer class of man-of-the-match Beauden Barrett, ended in control, with Richie Mo’unga and Barrett kicking the settlers that sealed a convincing 23-13 victory.

The world champions started off with a new-look haka, captain Kieran Read and TJ Perenara enjoying a double act in leading the ritual, and then Mo’unga and Barrett put on their own striking duet, leading New Zealand’s fluid attack to deliver moments designed to send a shiver through the rest of the contenders who, if they weren’t sure before, were reminded that this is still the team to beat.

"Fortunately, we came out on top, but it was another titanic struggle between New Zealand and South Africa. Hopefully, people got excited by it," Hansen said.

"I think they won, I don't think we lost it," conceded Rassie Erasmus, his Springboks counterpart. "Two tries to one, they definitely deserved to win. For me, they’re definitely the favourites."

Yet the frightening aspect is that Hansen's men can play better, and surely will. Their victory puts more onus on Ireland and Scotland, who meet on the same pitch tomorrow, knowing that playing the winner of Pool B now looks even more like a fate to be avoided in the quarter-finals.

Still, though, South Africa had some reasons to be cheerful, not least in the electric World Cup debut of Kolbe, a little flying machine in a scrum cap who inspired the second-half comeback with some remarkable running, bouncing off defenders as if in a giant pinball machine until his first, rejuvenating break for the team was nailed by a wonderful last-ditch cover challenge from Mo'unga. "It might have been a match-winner," Hansen reckoned.

Yet though they swarmed into attack from the start, dominating territory and possession in the opening 20 minutes and going ahead through an early Pollard penalty, South Africa rarely looked inventive enough to break through the black wall.

What a contrast when turnover ball allowed their suffocating press to be lifted. First, a careless Faf de Klerk pass gave Mo'unga the chance to pounce and hack on down the field and then level affairs with the subsequent penalty, which then proved the signal for three minutes of Springboks calamity.

When Duane Vermeulen spilled the ball, Mo'unga demonstrated his quality with a delightful cross-pitch kick, which enabled Sevu Reece to blitz past Makazole Mapimpi and eventually set up Barrett to race into the gap and put in young Crusaders wing Bridge for his eighth try in just six Tests.

Barrett's younger brother Scott then galloped in for a second after a sleight of foot off the left wing from centre Anton Lienert-Brown left four defenders flailing.

After the break, Kolbe was magnificent, covering 118 metres with his seven breaks, making twice as much ground as any other individual before cramp finally took hold.

Yet Savea, whose brother Julian made such a massive impact in 2015, proved just as influential, muscling past five defenders and wrestling two key turnovers.

Naturally, though, it was Beauden Barrett who led the charge. "On his day, he's the best player in the world and we saw that tonight," said Aaron Smith. "When Beauden Barrett wants the ball, you just give it to him and watch out."

The rest of the rugby world has now been warned to watch out, too; some things never change. 

RNS ic/djk/ajr/sw/mr