Not quite two days that shook the world of rugby then. Argentina yesterday briefly threatened to usurp Japan’s astonishing win over South Africa when leading New Zealand 16-12 early in the second half before the holders and favourites pulled through 26-16.

That at least crystallised Ireland’s task to win Pool D and thereby, almost certainly now, avoid New Zealand in the quarter-finals. Not that los Pumas, the likely opponents for the Pool D winners, look any less threatening than ever.

The reverberations from Japan’s 34-32 win over the Springboks could be felt throughout the tournament, including the Irish squad.

They stopped off for lunch in Stratford-upon-Avon during their three-hour coach trek from Cardiff to their new base in the St George's Park Hotel in Burton-on-Trent, the English FA-owned and purpose-built sports complex built at a cost of £156 million (€214 million). They have a clean bill of health, with Robbie Henshaw expected to play against Romania next Sunday.

Wasting time

"We've only been here a couple of hours but it's very impressive already," said Johnny Sexton. "Everything is on site. We don't have to be wasting time on buses going to training and that saves a couple of hours a day so we can get recovery in and it's great for the preparation that we've got this facility. We'll try to make the most of it."

Now ever more mindful of tier two teams, the Irish players were also still in amazement over witnessing the Japanese win, which could be backed at up to 100/1. They watched the first-half on a screen in their dressing-room at the Millennium Stadium, believing South Africa would pull through, before arriving back in their hotel team room for the last 20 minutes to witness what scenes that provoked uncomfortable reminders for those survivors who were nearly mugged by Georgia in Bordeaux eight years ago.

“We saw the best part of the game,” said Sexton. “Most of the squad were in the team room. A lot had gone up to their rooms to pack up. It was a good atmosphere in there as well. It was just exciting to watch it, except for the guys involved in 2007. They were saying that it re-enacted the Georgia match; that final play when holding out on the line. It just showed what could have happened eight years ago.”

Japan did it by playing rugby too. “I thought they were outstanding,” said Sexton.

"They deserved to win. They got five points – they got their bonus point as well, which was unbelievable. They played great rugby. They seemed really well coached. They obviously have top-class coaching team with Steve Borthwick and Eddie Jones. The players are always going to play for the jersey. They're a very proud nation.

Outstanding

“You add all those things together and they were outstanding. It’ll even give sides like us a boost going into tests ahead when we play bigger teams, and we’re going to feel like we have a chance. When you see those performances, they inspire everyone.

“Now it will be our turn to go out and play against a tier two nation and when the crowd gets behind them,” added Sexton. “I suppose we’re lucky that we’re going to get big crowds for the Irish. The neutrals were all going for Japan, and we probably won’t have many neutral supporters because the Irish will have the tickets.

"But against Romania we have to realise that these tier two teams are at their best come a World Cup and it's not like playing a November international when they're pulled together from all parts of the world for a one-off game. They've been together for a few months and they can produce big performances."

Romania have been disadvantaged though, by a classic minnows’ draw as they open their campaign against France in Milton Keynes on Wednesday and must pitch up against Ireland four days later.

Sexton’s one-time coach at Leinster, Michael Cheika, summed up Japan’s  win by commenting;  "I think it shows the great values that people have to have. You've always got to have that readiness in rugby because it's a contact sport. It's a game where the humble usually succeed, you know what I mean?” added the Wallabies coach.

“In any one contest, you might go good in one scrum and then you might get pushed off in the next one. You've just got to be on all the time.”