When it comes to shocks in international rugby it is a relative term, with the All Blacks losing to finalists France in two memorable World Cup games and Wales upset by Fiji in a shoot-out for a quarter-final slot among the most notable.
When it comes to shocks in international rugby it is a relative term, with the All Blacks losing to finalists France in two memorable World Cup games and Wales upset by Fiji in a shoot-out for a quarter-final slot among the most notable.
Amanaki Mafi of Japan celebrates at the final whistle of their historic Rugby World Cup win over South Africa. Photo: PHOTOSPORT
Wales's home defeat by Western Samoa in Cardiff in 1991 was generally regarded, until Sunday when Japan stunned South Africa, as the biggest upset in the eight tournaments to date. But as time has passed and people recognised the talent of the then-little known Pacific islanders, it seems far less seismic.
The same applied to Italy, who shocked Scotland in their first game after being added to the Six Nations championship in 2000, but who have gone on to record wins over most of their European rivals subsequently.
France's opening night World Cup defeat by Argentina in Paris in 2007 also looked less shocking as the Pumas went all the way to the semi-finals and beat the French again in the third-place playoff.
Tonga joined Fiji and Samoa by taking a top tier World Cup scalp when they beat France in 2011, but the Pacific island teams are no longer minnows of the game.
No amount of time, however, will diminish the impact of Japan's victory over twice-champions South Africa in Brighton.
After being excluded from the first two tournaments because of Apartheid, South Africa have a daunting World Cup record.
Champions in 1995 and 2007, third in 1999 and quarter-finalists in 2003 and 2011, they have punched their weight as one of the sport's traditional super-powers, previously losing only one pool game, to eventual champions England 12 years ago.
Japan could not be more different. A solitary win over Zimbabwe back in 1991 and two draws with Canada were the sole bright spots in seven previous campaigns.
Their dubious claim to fame was being on the wrong end of the all-time heaviest World Cup thrashing, when they were humiliated 145-17 by New Zealand in 1995, leaking 21 tries in the process.
Now, however, they will take their place alongside the likes of club sides Newport, Llanelli and Munster who somehow managed to defeat the All Blacks in their prime in the 1960s and 70s, as true giant-killers.
Japan's Australian coach Eddie Jones must have had a feeling in his water when he said this week: "It's David v Goliath".
"They've got the greatest winning record in World Cup history, a massive, physical team with experience.
"We've got the least winning record at the World Cup and we're the smallest team in the tournament."
Small in stature, but huge in heart, their attitude was summed up by their decision to eschew a guaranteed three points from an injury time penalty in front of the posts that would have secured a draw - still by far what would have been the high water point of Japanese rugby.
They opted to scrum again against the depleted Springboks and their bravery paid the most handsome of dividends when Karne Hesketh scored the match-winning try to set the tournament on fire.
As hosts of the next tournament in it could not have come at a better time for Japan, or for the sport.