TOKYO, 28 Sep - Former New Zealand winger John Kirwan says it would be "amazing" for the rugby world if Japan qualified for the knockout stages.
The hosts, who launched the tournament with a nervy 30-10 victory over Russia, are in a tight Pool A battle, with Samoa and Scotland also looking to qualify along with favourites Ireland.
And it is Japan's final game against Scotland in Yokohama City on 13 October that Kirwan, who coached the Brave Blossoms from 2007-2011, reckons could be key to their quarter-final chances.
Scotland began their campaign with a 27-3 defeat by Ireland and have since seen two key players, Hamish Watson and Ali Price, return home through injury.
"If Japan get through their pool it would be amazing for the game," said Kirwan, who scored a try in the final against France as the All Blacks won the first World Cup in 1987.
"It would be outstanding for the tournament if Japan qualified for the knockout stages.
"When I arrived to coach here we were 19th in the world. When I left we were 11th, they are ninth now and had that fantastic win against South Africa in 2015.
"The whole idea of bringing the World Cup to Asia was to open Asia and let’s hope they get through, but if they do, that will be to the detriment of a pretty established nation.
"Japan have a big game against Samoa (5 October) but I don't think it's their biggest game. I think it is going to come down to the Scotland game.
"Scotland were horrible against Ireland - it was a big surprise to me - and I don't think they can play that badly again.
"It is better to play like that at the beginning of the tournament so they can still salvage their tournament. They've lost a couple of players since then, so when it rains, it pours.
"If you look at FIFA you don't know who is going to win the (football) World Cup, and there are more teams getting better. That needs to be our model as well. We need some of these other nations getting through (to the latter stages)."
Kirwan is expecting the World Cup to become even more intense amid the battle to qualify for the knockout stages.
Apart from Pool A, Kirwan believes there is still all to play for in Pools C and D where Australia and Wales face each other in a pivotal match at Tokyo Stadium on Sunday.
But he knows his fellow Kiwis are still the team to beat as they bid for a third World Cup triumph in succession.
"I think Wales are one of the favourites, and Australia recently have been inconsistent. They can play outstanding rugby and they can drop the ball.
"But you can't write Australia off as they always turn up for World Cups.
"Gats (Wales head coach Warren Gatland) has got the nucleus of a pretty experienced side that have been to World Cups before. But we (New Zealand) will be a hard team to beat here.
"I can probably name six of the eight quarter-finalists but the other two are really interesting. Argentina are in trouble now after losing to France in Pool C. They are going to have to do something special, which is possible.
"But then is it going to be Japan or Scotland to fill one of those other two spots? I think the standard of rugby has been good. There haven't been any games where you're thinking 'this is boring me'. There has been some really good, free-flowing rugby.
"The opening week was good, but now it really gets more interesting."