"Japan just turned the World Cup upside down, and boy did the tournament need it. What was looking like a predictable procession to the quarter-finals for all the main teams has suddenly become anything but.
"Now Ireland are looking nervously over their shoulders in pool A, Scotland are in serious danger of not getting out of the group, Samoa, who already have a win and face the Scots on Monday, can dare to dream, and South Africa, who seem destined to finish as runners-up in pool B, might now have an easier route to the final than New Zealand.
"Japan must now be favourites to win the group, and if they do, they will face South Africa in the quarter-finals, leaving Ireland to take on the All Blacks. Who says fate doesn't have a sense of humour?"
"Ireland came to Japan hoping to make history but this wasn't what they had in mind.
"On an unforgettable evening in front of 47,813 fans in Shizuoka, the World Cup got a turbo-charge thanks to a stunning display from hosts Japan who put themselves on course for a first quarter-final with a performance for the ages.
"They had to do it the hard way, coming back from a 12-3 deficit after Ireland took control in the opening quarter. They kept Ireland scoreless for more than an hour and the visiting team grew more desperate and disjointed.
"This was, for sure, some day for Japanese rugby and as an extension some day for the 2019 Rugby World Cup, but it was a deeply disappointing and damaging defeat for Ireland.
"In the process, the Brave Blossoms blew Pool A wide open, and although Ireland secured a bonus point – which was the most their performance deserved – to win the group and, most likely, avoid the All Blacks in the quarter-finals, they now need Scotland to beat Japan, providing Japan fail to pick up bonus points from their remaining fixtures. But this is now a three-way tussle. Ireland need a handsome, 10-point return from their remaining games against Russia and Samoa.
"But the feel good factor generated by the handsome win over Scotland has been largely eroded."
Japan coach Jamie Joseph: “we were thinking about this game for a long time, Ireland were only thinking about it for the last six or seven days.” #JAPvIRE#RWC2019
Japan's incredible upset over Ireland, in a repeat of their Brighton miracle at the last Rugby World Cup, has thrown the All Blacks' quarter-final opponent wide open.
Technically the All Blacks are yet to qualify for the quarter-finals but having repelled the Springboks and with Canada, Namibia and Italy in the coming weeks the greatest upset in World Cup history would be required to prevent Steve Hansen's men topping their pool.
Who the All Blacks will face in the first knockout round, though, promises to be a fascinating subplot.
As it stands it could be any one of Japan, Samoa, Ireland or Scotland.
Former Ireland captain Brian O'Driscoll, a pundit on ITV's coverage, said: "The mood of the whole country has shifted in 80 minutes.
"I for one didn't see that happening. I knew it would a tough game, they are the host nation, they have nothing to lose, but huge credit to Japan, they played terrific rugby but Ireland looked very blunt, they looked devoid of ideas, devoid of energy actually.
"I wonder if the humidity took effect because it wasn't the Ireland we have come to expect.
"It's very disappointing, it's not the end of the tournament, they can still top the pool but gosh they have so much to work on to even think about getting beyond the quarter-finals at this stage."
Love your rugby? Subscribe now to NZ Herald Premium for unlimited access to premium content, including our exclusive, first-class rugby coverage. Check out our special rugby offer here