Chris Rattue: Sport doesn't get more stunning than this

Japan players celebrate their surprise victory during the 2015 Rugby World Cup Pool B match between South Africa and Japan. Photo / Getty Images.

South Africa 32
Japan 34

This is the biggest upset in the World Cup, in any sport, EVER. Or that's what it feels like for now.

Japan's victory over the Springboks is so stunning that it is almost in a league of its own. In the end, if the Springboks can re-group, it might not make a huge difference because of the way Pools A and B are set up.

Japan has a chance now in the pool which includes Samoa and Scotland.

But who cares about the ramifications for now, because this is bigger then Ben Hur as the old saying goes. This is like Daffy Duck out-running Lewis Hamilton, a New Zealand tennis player beating Roger Federer. This is what great international sport should be all about, and it is a fantastic shot in the arm for world rugby.

When upsets were contemplated before the tournament began, nobody would even have considered this one. Not in their wildest dreams.

The only form guide - in hindsight - was Japan's impressive burst against France during the last World Cup, when they threatened to beat the eventual 2011 finalists in their match at North Harbour Stadium.

Image 1 of 10: Ayumu Goromaru of Japan tackles Jean De Villiers of South Africa. Photo / Getty Images

A form guide - on the other side of the coin - was the Springboks' shock home loss to Argentina and the ructions caused by the failure of South African rugby to satisfy those who are calling for faster racial transformation.

But honestly, nothing explains this result. The All Blacks would be expected to beat this Japanese side by a good 50 points. For South Africa, it should have been a cake walk.

Unlike a sport such as football, heavy favouritism in rugby is harder to overcome because of the sheer physical advantages.

South Africa might not be in their finest shape, but they are one of the great sides of world rugby history, with a fully professional set of Super Rugby teams underpinning their national side. Japan can't even raise a Super Rugby side with any conviction.

The Japanese have off-cuts from other nations, although their captain Michael Leitch is a class act. Leitch might be described as Kiwi, and he certainly hails from New Zealand.

But he went to Japan as a 15-year-old and became captured by life there. He is very Japanese, in other words.

Yet even Leitch, a star for the Chiefs this season, did not want to play for their new Super Rugby outfit and has stayed with the Chiefs. That's how down the pecking order Japanese rugby is.

Japan by the numbers:

World Cup matches: Played 25, lost 21, won 2, drew 2.
Last win: v Zimbabwe, 1991
Odds on beating South Africa: 40 - 1
Their 2015 pre-World Cup record: Beat: Korea, Hong Kong, Canada, Uruguay, Georgia.
Lost to: USA, Fiji, Tonga.

Their World Cup match list
1987
Lost - Japan 18 USA 21
Lost - Japan 7 England 60
Lost - Japan 23 Australia 32
1991
Lost - Japan 9 Scotland 47
Lost - Japan 16 Ireland 32
Won - Japan 52 Zimbabwe 8
1995
Lost - Japan 10 Wales 52
Lost - Japan 28 Ireland 50
Lost - Japan 17 New Zealand 145
1999
Lost - Japan 9 Samoa 43
Lost - Japan 15 Wales 64
Lost - Japan 12 Argentina 33
2003
Lost - Japan 11 Scotland 32
Lost - Japan 29 France 51
Lost - Japan 13 Fiji 41
Lost - Japan 26 USA 39
2007
Lost - Japan 3 Australia 91
Lost - Japan 31 Fiji 35
Lost - Japan 18 Wales 72
Draw - Japan 12 Canada 12
2011
Lost - Japan 21 France 47
Lost - Japan 7 New Zealand 83
Lost - Japan 18 Tonga 31
Draw - Japan 23 Canada 23

Japan celebrate their winning try. Photo / Getty Images.