Two-time defending champions New Zealand ran nine tries past Canada in a 63-0 romp to strengthen their grip on Pool B at the Rugby World Cup on Wednesday.

All three Barrett brothers -- Jordie, Beauden and Scott -- scored tries as the All Blacks totted up four before half-time and added another five in the second period.

Brad Weber, back in the All Blacks after being sidelined for four years, was the inspiration the defending champions needed to set their second half alight.

The quick-thinking Weber, coming on as a replacement at the start of the second half, scored two tries himself and was instrumental in the other three.

"I thought particularly that first half of the second half, they really came together and played good controlled rugby," said All Blacks coach Steve Hansen.

"In really difficult conditions -- the humidity is unbelievable, and whilst people at home will be wondering why we dropped a few balls, it's very, very difficult. So I think they've done well."

In a messy first half, where the clammy conditions inside the roofed Oita Stadium contributed to multiple handling errors, the All Blacks only led 28-0 at half-time.

But with Weber dictating the flow they doubled that score in a frenetic opening 10 minutes of the second half with four rapid tries.

They only scored one more as the energy-sapping conditions took their toll, but it was enough to post the highest score in this World Cup so far. 

However, the All Blacks finished short of the 79-15 scoreline when they last played Canada at the 2011 World Cup.

The try-scoring Barrett brothers became the first sibling trio to start a World Cup match for the All Blacks, and history was also made late in the second half when Ardie Savea, who is battling vision problems, became the tournament's first player to wear protective goggles.

'True grit'

The New Zealanders, wearing black arm bands as a mark of respect for former All Blacks lock Stan 'Tiny' Hill, who died aged 92 just a few hours before kick off, needed only four minutes to get their first points on the board. 

They were awarded a penalty try when Canada scrum-half Gordon McRorie dived into a scrum to prevent a pushover try. 

Jordie Barrett latched on to a Richie Mo'unga cross-kick for the second try, and Sonny Bill Williams added the third with a simple dummy and sidestep for 21-0 lead after 16 minutes.

Canada had the crowd on their feet when a McRorie intercept put fly-half Peter Nelson in the clear, but he was cut down just short of the line by Beauden Barrett. 

The plucky Canadians also turned down the chance of three easy points by electing for a lineout rather than a shot at goal when All Blacks skipper Kieran Read was penalised for a no-arms tackle. 

It took until just before the break for the All Blacks to secure their four-try bonus point when Beauden Barrett snapped up a Williams grubber kick to cross near the posts. 

Rieko Ioane, who has been in a form slump, needed only 43 seconds to open the second half scoring.

Scott Barrett, who spilled the ball when diving for the line in the first half, made no mistake when given a second opportunity before Shannon Frizell and Weber's double closed out the scoring.

"The way we dug in the last 20 minutes, I'm proud of the guys. They showed true Canadian grit," said Canada coach Kingsley Jones.

"Every one of them can look themselves in the mirror and be proud of their performance tonight."