Watching the last fixture of the Rugby World Cup pool stages on Sunday night between Japan and United States confirmed one thing -- the term 'Tier Two' might need to be re-addressed sooner rather than later. It was a match that provided two more high quality performances from sides that before the tournament were seen as making up the numbers.

Japan have stolen my heart over the past three weeks. I'm trying to find some sort of Japanese heritage as we speak. When you see what their progress means to them (including Ayumu Goromaru who was in tears after receiving his second man-of-the-match award) it makes you realise the rugby landscape has changed forever.

Everyone will remember Japan and their heroics during their win over South Africa but don't forget that the Brave Blossoms, hosts in 2019, also beat the USA and stormed past Samoa. Had they not had to back up one of sport's major upsets by facing Scotland just four days later, who knows what might have happened -- they could have even topped the group. The game against Vern Cotter's men was close until the second half when it became clear fatigue was playing a part. Japan have certainly closed the gap.

Karne Hesketh scores the match-winning try for Japan against South Africa© Charlie Crowhurst/Getty Images

I'm convinced USA are a sleeping giant and their participation in next year's Olympic Games will thrust rugby into every American's heart. Their resources combined with players who don't quite make the cut in American football means we will see household names of the future. Don't forget that many of these will be some of the best athletes in the country. Look at Thretton Palamo playing in the centre, a former running back. His physical capabilities combined with rugby development over the next four years will mean, come 2019, he will be a nightmare to play against. Take Samu Manoa as a current example.

Samoa should arguably have beaten Scotland last Saturday in Newcastle. If Ray Lee-Lo had picked off one of the simplest two-v-ones and sent Paul Perez over, Samoa would have won. They undoubtedly have had a poor tournament but I think this is more a reflection of what is happening within the Union, which has led to real instability.

Their performance against the Scots was at times amazing. Yes, there were moments of madness that created problems but the fundamentals are there. Scan all of the team sheets of Samoa, Tonga and Fiji and there are world class names scattered throughout. Nemani Nadolo, Vereniki Goneva, Nikola Matawalu, Nili Latu, Sione Kalamafoni, Tim Nanai-Williams, Kahn Fotuali'i and Jack Lam. Proper players who can make a dent on the world game. Should the foundations of the game in these countries create a decent platform for their professional players, performances will improve. The hardest thing for these sides is getting the players together on a regular basis to train. Their squads are dotted all over the world and logistically it is a nightmare. Simple changes and regular fixtures would help all of the nations in the Pacific Islands.

Georgia's performances have improved massively since the last two World Cups. Most of their players play in France within the Top 14 and Pro D2 exposing them to a high level of competition and they have been led from the front by Mamuka Gorgodze. He was even man of the match in their loss against New Zealand. Their result against Argentina reflects where the South Americans are rather than the Georgians. Their ability to defend against some dangerous Tongan runners for so long showed real discipline and defensive understanding. They made more than 200 tackles, a phenomenal feat in Test rugby.

Mamuka Gorgodze looks on after Georgia's World Cup clash against the All Blacks© Richard Heathcote - World Rugby/World Rugby via Getty Images

Romania and Canada had very similar results. They weren't sent packing as some might have thought. Both frustrated the French and pushed Italy all the way. Players like Valentin Ursache and Catalin Fercu for Romania, with DTH van der Merwe and Jamie Cudmore for Canada, are all clear examples that these countries are capable of producing top players and that their development over the next four years is key to them demonstrating continued progress in the next World Cup.

We regularly see players from these countries in the English, French and Italian leagues which helps. Namibia are the one side seriously underpowered -- it doesn't help when you have less than 10,000 registered rugby players. That said, they seriously frustrated the All Blacks at the Olympic Stadium. For them to keep up with the progression of other sides they are going to have do something out of this world. However, you can't say that watching them was anything other than a pleasure -- farmers and teachers giving their all against top professionals like Ma'a Nonu and Richie McCaw.

© Laurence Griffiths/Getty Images

The days of teams being beaten by a hundred points or more have gone. The professional game is now truly global and the effects are rippling throughout the countries regularly involved in the Rugby World Cup. We can expect to see upsets in every competition from now on. Japan 2019 seems like a long way off but it will give the Tier Two sides enough time to continue their progression, in the hopes of emulating Eddie Jones' humble Japanese side.

It will take time but I know everybody would love to see it happen again. Perhaps the sleeping giant of the United States will have woken from its slumber by then. If so, look out world.