When the flame was extinguished at the Maracana on Sunday, so ended the Olympic careers of some of the finest sportsmen and women to have lived.Rio was our last chance to delight in the talents of sprinter Usain Bolt, swimmer Michael Phelps, cyclist Sir Bradley Wiggins and heptathlete Jessica Ennis-Hill on the biggest sporting stage of all.
While British cyclists Laura Trott and Jason Kenny, and American decathlete Ashton Eaton, among others, are young enough to continue to carry the torch of Olympic greatness, new stars must come to the fore for Tokyo 2020.
The list is not definitive - and no-one knows what the future will hold - but here we select 10 athletes who could be the headline acts in four years' time.
Jon Dibben (Great Britain) - track cyclingWith a stunning attack on the final sprint to win gold, Dibben stirred the 8,000-strong crowd during the points race at the World Championships earlier this year.
It was a performance that had team-mate Owain Doull tweeting of his tears.
The world champion - and European omnium bronze medallist - was also part of the men's team pursuit that won world silver in London in March.
But the 22-year-old Team Wiggins rider was not selected for Rio, with Mark Cavendish - who went on to win omnium silver - preferred.
The 30-year-old Manxman is unlikely to compete in Japan and with Rio also being Wiggins' Olympic farewell, Tokyo could be Dibben's time.
Lois Toulson (Great Britain) - divingRio 2016 saw Britain's 'other' divers come to prominence. Jack Laugher became the nation's most successful diver in Olympic history with gold and silver, while Dan Goodfellow ably supported Tom Daley as the pair won 10m platform synchronised bronze.
Daley is still his sport's headline act, but the 22-year-old cannot twist and tuck forever and failed to reach the 10m platform final.
Step forward Toulson, at 16 one of the youngest British athletes competing in Brazil. The teenager from Huddersfield was accustomed to winning medals in junior championships and was ranked third in the world, with partner Tonia Couch, in the women's synchronised 10m prior to the Games.
Toulson - who will soon receive her GCSE results - and Couch did not finish in the top three in Brazil, extending Britain's run without a women's Olympic diving medal to 56 years, but Tokyo could be the city where the long wait ends.
Ellie Downie (Great Britain) - gymnasticsMany a British gymnast will return home with their reputations enhanced and names in British sporting history - such as double Olympic champion Max Whitlock, 16-year-old bronze medallist Amy Tinkler and Nile Wilson, the high bar Olympic bronze medallist.
It was a record seven Olympic medals for Britain's gymnasts, but amid the celebrations, it is easy to forget those who did not win a medal.
Downie, the first British woman to win an all-around medal at a major gymnastics championships, described Rio as a "rollercoaster experience".
She fell on her neck during the qualifying stages and went on to finish 13th in the all-around, but the Nottingham athlete will only be 20 when the Olympic flame arrives in Japan and, along with Tinkler, could by then be matching the world's best somersault for somersault.
Andre de Grasse (Canada) - athleticsThere will be no Bolt at the next Olympics to inspire and entertain. While no-one can replace the greatest track and field athlete who has ever lived, De Grasse could be the man to dominate men's sprinting once the nine-time Olympic champion says his final goodbyes to the sport.
The 21-year-old, who only took up athletics seriously four years ago, recorded personal bests in both the 100m (9.91 seconds) and 200m (19.80 seconds) in Rio. He went on to win three medals - 200m silver, 100m bronze and sprint relay bronze - to become the first Canadian since 1932 to win three medals at the same Games.
"He has a lot of talent," Bolt has said of De Grasse, who himself has made clear his intentions. "It's a dream come true for me," he said of his Rio spoils. "For next time around, I just want to upgrade those medals."
Ben Proud (Great Britain) - swimmingIt is Adam Peaty, the Olympic champion and world record holder, who will return to Britain as the nation's swimming superstar.
But in Tokyo, he may have to share the limelight with 21-year-old team-mate Ben Proud, the man acknowledged as the fastest junior swimmer in history.
Proud set a new British record of 21.54secs in qualifying for the 50m freestyle final and went on to finish fourth - 0.19secs adrift of 35-year-old champion Anthony Ervin.
His performances in Rio have strengthened many people's belief he could become the world's fastest swimmer. They enhanced the reputation he gained two years ago in winning double Commonwealth gold - an achievement that included a stunning swim to beat South African heavyweights Roland Schoeman and Chad le Clos to the 50m butterfly title.
Japan - men's rugby sevensFiji have dominated men's rugby sevens for decades and it was the Pacific islanders who beat Britain emphatically in the final to become Olympic champions.
But semi-finalists Japan played their part in the sport's successful Olympic debut, rocking the old order by beating New Zealand in sevens for the first time in 17 attempts and rekindling memories of the Brave Blossoms' sensational victory over South Africa at last year's Rugby World Cup.
Described as an "outstanding team" by Britain's coach Simon Amor, Japan's magnificent seven would also have drawn with Britain but for a missed late conversion by Lomano Lemeki.
Such was the impact of their success, Japan's players were told to turn off their phones because of the number of supportive messages they were receiving from home.
Japan will host the next World Cup in 2019 and, with the Olympics in Tokyo the following year, both formats of the game could take hold in the country.
Dina Asher-Smith (Great Britain) - athletics"This is for the entire nation," said Dina Asher-Smith after winning sprint relay bronze, Britain's first medal in the event since Los Angeles 1984.
Britain's fastest woman will end her first Olympics with a medal and an individual fifth-place finish in the 200m. For a 20-year-old who combines athletics with studying for a history degree, that is no small feat.
Four years ago, Asher-Smith was a kit carrier at London 2012 and since then has gone on to become the first British woman to win the European 200m title, plus the British record holder over 100m and 200m and, in finishing fifth at last year's World Championships, the fastest teenager ever over 200m.
She is almost certain to create more history over the next four years and, who knows, could become the first British female to win Olympic medals over 100m and 200m since Dorothy Hyman in 1960.
Kanak Jha (US) - table tennisTokyo 2020 could be the Games where Kanak Jha - the first American born in the 2000s to qualify for Rio - will come of age.
The 16-year-old has been described as a table tennis prodigy. Even though he failed to progress in Rio, the youngest male player to compete in his sport at an Olympics has potential.
"When he was six or seven years old, he just had that knack," his father Arun has said. As a junior, this Californian son of Indian parents reached the national semi-finals of the men's senior tournament.
Can he help break China's hegemony over the sport? They have won 28 of the 32 gold medals since table tennis made its Olympic debut in 1988 so it is a tall order, but any teenager who moves from the US to Sweden to hone his skills is clearly planning for a big future.
Missy Franklin (US) - swimmingIt might seem strange to name a five-time Olympic champion as a potential headline-maker, but for Missy Franklin, Tokyo could be the Games where her star is reborn.
The American cleaned up in the pool in London 2012 when she was just 17, winning five medals - four of them golds. Yet she did not advance to the final in either of her individual events in Rio - although she did win relay gold.
She appears not to have regained form or confidence following a back injury in 2014 and was upstaged in Rio by Katie Ledecky, her country's new darling in the pool. Franklin described her performances in Brazil as heart-breaking, but could she become Phelps-like again in Tokyo? It will be interesting to find out.
Kenzo Shiral (Japan) - gymnasticsJapan has grown accustomed to dominating men's gymnastics, with Kohei Uchimura, the two-time all-around Olympic champion, their superstar.
The 27-year-old is a great of his sport, winning 10 world titles as well as three Olympic golds, but whether he can still dominate in four years' time and win a record third consecutive all-around gold is open to question.
The man who could be the heir to Uchimura's throne is 19-year-old Shiral. In 2013, aged 17, he mesmerised on the floor to become world champion on that apparatus and retained his title in 2015.
He surprisingly failed to shine on the floor in Rio, with Britain's Whitlock claiming gold, but that should not rule him out of potentially vying for Olympic titles on home soil. He did, after all, win team gold and vault bronze in Brazil.