|People opposed to the Tokyo 2020 Olympics display placards during a rally in the city on March 24 AFP/Kazuhiro NOGI
The dramatic step to shift Tokyo 2020 to next year had never before been seen in peacetime and the postponement upends every aspect of the organisation - including venues, security, ticketing and accommodation.
"It's like taking seven years to build the world's biggest jigsaw puzzle and, with just one piece to go, having to start again but now with less time to finish," tweeted Craig Spence, spokesman for the International Paralympic Committee.
It is not even clear exactly when the rescheduled Games will take place, with the International Olympic Committee saying the new date would be "beyond 2020 but not later than summer 2021".
Japan had always framed Tokyo 2020 as the "Recovery Games" - a chance to show the world it had bounced back from the "triple disaster" in 2011 when a massive earthquake sparked a tsunami and the Fukushima nuclear meltdown.
The delayed event - still to be called Tokyo 2020 - will now be a "testament to mankind's defeat of the new virus", said Japan's Prime Minister Shinzo Abe.
The Games could stand as a "beacon of hope to the world during these troubled times" and the Olympic flame "could become the light at the end of the tunnel in which the world finds itself at present", Japan and the IOC said in their joint statement.
"WAY BIGGER THAN ME"
The Olympics, which has weathered boycotts, terrorist attacks and protests, is the highest-profile event affected by the virus that has killed thousands and postponed or cancelled sports competitions worldwide.
The IOC had come under fire for appearing out of touch by sticking to its schedule, but it eventually bowed to the inevitable, citing the need to protect the health of athletes.
Bach said the postponement was "about protecting human life", with more than 11,000 athletes expected at the Games along with 90,000 volunteers, and hundreds of thousands of officials and spectators from all over the world.
US swimming star Ryan Lochte summed up the combination of disappointment and relief expressed by most athletes, after many had voiced anger at being asked to continue training during the pandemic.
"I was a little pissed off because I've been training my butt off and I've been feeling great," the 12-time Olympic medallist told the Los Angeles Times.
"But this whole thing is way bigger than me," Lochte added. "It's way bigger than the Olympians, it's affecting the entire world right now."
There were similar feelings on the streets of Tokyo, which had won widespread praise for its preparations, with tickets flying off the shelves and venues completed well ahead of schedule.
The Olympic rings are up and the cute wide-eyed mascots are plastered across billboards and commuter trains all over the city but most people in the megacity said sense had prevailed.
"It is disappointing for sure, but when you think about the health of athletes as well as spectators, I understand," IT engineer Momoko Doku told AFP on the bustling Shibuya crossing.
"The new coronavirus is spreading so fast in the world, and this is a very serious issue internationally," he said.
The Japanese media were also broadly supportive, although the Tokyo Shimbun daily screamed "surprise and embarrassment".
"It is like all the efforts of the last seven years are back to square one," the Nikkei business daily said.
"LET US HOPE"
The Olympic torch relay, due to begin from Fukushima on Thursday, has been scrapped but the flame will stay in the area until it is safe to begin.
And organisers now have to wrestle with a host of unanswered questions: Are the venues still available? What to do with ticket-holders and volunteers? How to fit the Games into a crowded 2021 sporting schedule?
The athlete's village was due to be renovated into more than 4,000 luxury apartments for sale with hundreds already snapped up. Tens of thousands of hotel rooms will need to be cancelled and rebooked.
Japan and the organising committee were spending US$12.6 billion on the Games and experts say they may need to spend around half that again to rearrange the event - before hopefully recouping the losses when the Olympics are held.
Tokyo 2020 President Yoshiro Mori, an 82-year former prime minister and cancer survivor, pointed to his own health battles as inspiration for the difficult times ahead.
"We have no choice but to have hope. I myself suffered cancer ... But I was saved by a new drug. I am here, allowed to live.
"Let us hope for these things."