Tokyo - New Zealand coach Steve Hansen paid tribute on Monday to an "awesome" Japan performance at the Rugby World Cup and said even the mighty All Blacks were glad to avoid them in the quarter-finals.

Japan have upset the form book and 50/1 bookmakers' odds by winning all their group matches, including against Scotland and Ireland, to top their pool and play South Africa in the last eight.

"People have said 'Who do you want to play?' Well, there's an in-form team so I'm quite happy they are on the other side of the draw," said Hansen.

New Zealand topped Pool B and will play their quarter-final against Ireland, who were stunned by the Brave Blossoms in their group match.

Describing Japan's 28-21 win against Scotland on Sunday as "awesome", Hansen said the Brave Blossoms now belonged at World Rugby's top table - the sport's so-called Tier 1 teams.

"Without a doubt, they would have to be considered like they are playing and performing like a Tier 1 nation," said Hansen.

"They are now in the top eight in the world on performance. They are playing quality rugby so I think Japan should be very, very proud," he added.

Japan have risen to seventh in the world rankings on the back of their World Cup form, above Six Nations sides France, Scotland and Italy, and Rugby Championship team Argentina.

All Black flanker Sam Cane said the Japan-Scotland match had packed out the TV room in the New Zealand camp, with about three-quarters of the squad watching it together and the rest viewing it in their rooms.

"Pretty impressive to be honest. First half was really impressive. The speed the Japanese played at. The skill level. They are the real deal," he said.

Centre Anton Lienert-Brown said Japan had been "outstanding" and "awesome" and highlighted their defensive effort as Scotland hit them with wave after wave of attacks in the second half.

"To see them holding out defensively as well was very impressive," said Lienert-Brown.

Hansen said Japan's run was a "marvellous thing" for the Rugby World Cup and had boosted the sport in the country, the first Asian nation to host the tournament.

He also said the win had lifted the country after a "pretty horrific weekend" being battered by Typhoon Hagibis, which has claimed at least 35 lives.