For the host nation, the Olympics fell short of the global triumph and financial blockbuster it once sought. Still, organisers appear to have prevented the Games from spiralling into a COVID-19 superspreader event, a remarkable achievement given that some 50,000 people came together amid the pandemic.

An April consolation prize of a Spanish Cup success -- his 35th club trophy -- was scant reward.

The Americans were 24-18 behind after the first quarter and 42-45 adrift at half-way, but stormed back during a dominant third term to stay on track for a fourth consecutive gold medal.

Apriyani Rahayu, 23, and her veteran partner Greysia Polii picked up the badminton-mad country's first Olympic gold medal in Tokyo on Monday, and its first-ever Olympic medal in the women's doubles.

The world No. 6 women's doubles badminton pair managed to beat second seed Chen Qingchen and Jia Yifan of China in a fierce straight set battle.

In the gold medal match, Canada will face the winner of the other semi-final between Australia and Sweden which is being played later on Monday.

The 33-year-old veteran and partner Apriyani Rahayu beat China's Chen Qingchen and Jia Yifan 21-19, 21-15 to pick up their country's first Olympic medal in women's doubles.

Punishing conditions greeted the athletes as a trackside thermometer in the open, placed about 50 metres from the finish line, touched 40 degrees Celsius (104°F) and the humidity hovered around 60 percent, with sun beating down on the fan-free Olympic Stadium.

Polii, 33, and Apryani Rahayu, 10 years her junior, beat South Korea's Lee So-hee and Shin Seung-chan 21-19, 21-17 on Saturday to move within one win of an unlikely women's doubles gold medal.

"Simone has withdrawn from the event final for floor and will make a decision on beam later this week. Either way, we're all behind you, Simone," USAG tweeted.

Lee and Wang's campaign in Tokyo got off to the worst possible start, losing their first match, before narrowly scraping out of the group stage.

Hendra/Ahsan, Greysia/Apriyandi advance, ‘Minions’, Jonatan suffer shock losses

The US superstar, 24, blamed "the twisties" for her dramatic exit from the team event at the Tokyo Games, where she was aiming to equal or even surpass the all-time women's gymnastics record of nine Olympic golds.

After her stunning exit from the women's gymnastics team event on Tuesday, Simone Biles said she felt she had been carrying the weight of the world on her shoulders. That burden seems to have been exacerbated by a year a grief, loss and restrictions tied to the COVID-19 pandemic.

Rahmat, who was only selected to represent Asia along with China, Japan, and South Korea in the Tokyo Olympics last month, told Reuters that the lift was “easy.”

"After further medical evaluation, Simone Biles has withdrawn from the final individual all-around competition at the Tokyo Olympic Games, in order to focus on her mental health," USA Gymnastics said in a statement.

Last week Medvedev was the first to appeal for a delayed start for tennis at the Tokyo Olympics due to the hot and humid weather conditions and also received support from world number one Novak Djokovic.

The superstar American gymnast Biles on Tuesday stunned the Tokyo Olympics when she pulled out of the women's team final, saying: "I have to do what's right for me and focus on my mental health and not jeopardise my health and my wellbeing."

Biles sent a shock through the Summer Games on Tuesday when she dropped out of the team competition on her opening vault after receiving a low mark.

Osaka, who lit the Olympic cauldron and was one of the faces of the Games, struggled in an error-strewn display that blew the draw wide open after the earlier exits of world number one Ashleigh Barty and third seed Aryna Sabalenka.

The world number two was swiped aside 6-1 6-4 by Czech Marketa Vondrousova in an early shock on Day Four of the Games.

The two athletes, one of whom is a Dutch tennis player, were both living in the athletes' village, according to the organizers. The others are three games-related officials, one contractor and a member of the organizing committee.

Osaka, the star of the opening ceremony, defeated China's Zheng Saisai 6-1, 6-4 and said she felt "refreshed" after taking an eight-week break for mental health reasons.

The action began early at Tsurigasaki Surfing Beach, about 100 kilometres (60 miles) east of Tokyo, with the first surfers paddling out in favourable wave conditions.

Indonesia's Jonatan Christie was competing at a tournament in Thailand earlier this year when he learned that his older brother, Ivan, had contracted the illness back home.

Bach's speech, which drew on familiar themes of peace, solidarity and gratitude for overcoming the coronavirus hardships, immediately drew ire on Twitter and in traditional Japanese media.

The team of Cate Campbell, Emma McKeon, Meg Harris and Bronte Campbell lowered the 3:30.05 Australia set at the 2018 Commonwealth Games to reinforce their dominance of the event.

Murray, 34, will stay in Tokyo to play doubles with Joe Salisbury. The pair won their opening match of the competition on Saturday. 

Barty, the reigning Wimbledon champion, dropped serve twice in each set as 48th-ranked Sorribes Tormo made just five unforced errors to the Australian's 27 to earn a shock win.

Teenager Windy Cantika Aisah took the bronze for Indonesia after smashing her personal best twice in the clean and jerk.