|Tokyo Olympic Games on the BBC|
|Dates: 23 July-8 August Time in Tokyo: BST +8|
|Coverage: Watch live on BBC TV, BBC iPlayer, BBC Red Button and online; Listen on BBC Radio 5 Live, Sports Extra and Sounds; live text and video clips on BBC Sport website and app.|
Jamaica's Elaine Thompson-Herah retained her Olympic 100m title with an electrifying run and American Caeleb Dressel swam a world record in the pool on day eight in Tokyo.
Thompson-Herah ran the second fastest time by a woman ever, setting an Olympic record of 10.61 seconds, as she led a clean sweep of medals for her country in the blue riband event.
Shelly-Ann Fraser-Pryce, who took silver, had been bidding to become the first woman to win a single individual Olympic athletics event three times.
The event lit up the Games on a day where a dark cloud hung heavy after two sprinters had earlier failed drugs tests.
Nigeria's Blessing Okagbare and Kenyan Mark Otieno Odhiambo were provisionally suspended after testing positive for banned substances in the first doping cases of these Games.
There was anger on the tennis court as world number one Novak Djokovic threw one racquet and smashed another as his bid for an Olympic medal came to an end, but relief in BMX as American racer Connor Fields was moved out of intensive care after suffering a brain bleed in a crash on Friday.
And there was heartbreak in athletics when injury-hampered British gold-medal hope Dina Asher-Smith failed to qualify for the 100m final and then pulled out of the 200m - an event in which she is reigning world champion.
Another pre-Games favourite, gymnast Simone Biles, raised further doubts about whether she will compete in Tokyo again after withdrawing from Sunday's vault and uneven bars finals.
These Olympics have been held under difficult circumstances because of the global pandemic and Covid-19 infections in Tokyo hit a record level on Saturday.
But the halfway point of the Games also brought some joy to the locals, with Japan celebrating their most gold medal wins ever after taking their tally to 17.
China lead the medal table with 21 golds, with Japan second and the United States (16) third.
Thompson-Herah defends title in style but heartbreak for Asher-Smith
Elaine Thompson-Herah's incredible run to a second successive 100m gold was just 0.12secs short of the 33-year-old world record set by American Florence Griffith-Joyner.
Shericka Jackson completed a Jamaican one-two-three with a time of 10.76, 0.02 behind Fraser-Pryce.
This has been a Games of shocks and upsets, probably unsurprisingly given the global situation.
And on the second day of action at the Olympic stadium, the athletics could not escape the trend.
Great Britain's Asher-Smith failed to make the 100m, later saying she had torn her hamstring earlier this month and that the injury had looked like it might stop her from even lining up in Tokyo.
"It broke my heart because I am a competitor," a tearful Asher-Smith told BBC Sport.
In the men's event, which is adjusting to the post-Usain Bolt era, there was almost an upset but gold-medal favourite sneaked through the first-round heats as a fastest loser.
The American, who is the fastest in the world this year, got off to a terrible start and finished fourth in his heat in 10.05 seconds. He then faced a nervous wait to find out if he would advance, with only the top three going through automatically.
He will need to improve considerably if he is to become the blue riband event's first American champion since 2004.
Canada's Andre de Grasse, bronze medallist at Rio 2016, was the fastest qualifier in 9.91 seconds.
Dressel & Ledecky win golds
American Caeleb Dressel claimed his third gold medal of the Games when he set a world record to win the men's 100m butterfly..
The 24-year-old touched home in 49.45 seconds.
Fellow American Katie Ledecky won the 800m freestyle gold for the third successive Olympics, while Australian Kaylee McKeown took gold in the women's 200m backstroke.
Meanwhile, Great Britain claimed a fourth swimming gold at an Olympics for the first time in 113 years by winning the inaugural 4x100m mixed medley relay in a world-record time.
Doping positives hit Tokyo
Nigerian Blessing Okagbare, who had won her 100m heat on Friday, was suspended before she was due to race in the semi-finals.
The Athletics Integrity Unit said the 32-year-old had tested positive for a human growth hormone following an out-of-competition test on 19 July.
Okagbare was an Olympic long jump silver medallist in Beijing in 2008.
A few hours later, Kenyan Mark Otieno Odhiambo was provisionally suspended just before he was due to run in the 100m heats.
Otieno Odhiambo denies any knowledge of the violation and has requested a re-test of his B urine sample.
Djokovic leaves Tokyo without a medal
In tennis, Serbian top seed Djokovic missed out on a medal, letting his frustration boil over as he lost the men's singles bronze-medal match to Spain's Pablo Carreno Busta 6-4 6-7 (6-8) 6-3.
Djokovic, 34, then pulled out of his mixed doubles bronze-medal match with an injury to leave Tokyo empty handed.
"I just didn't deliver yesterday and today," Djokovic told reporters. "The level of tennis dropped also due to exhaustion, you know, mentally and physically."
Later in the day, Belinda Bencic beat Czech Marketa Vondrousova 7-5 2-6 6-3 to become the first female Olympic tennis champion from Switzerland.
Biles pulls out of two more finals
Much of the focus of these Games has been on American gymnast Simone Biles, who had been favourite for multiple gold medals before she began suffering with the 'twisties'.
She has not competed since performing a vault in the team final on Tuesday, subsequently pulling out of the all-around final. On Saturday she announced she would not be competing in Sunday's vault and uneven bars finals.
USA Gymnastics said she would continue to be evaluated daily to see if she would compete in the floor final on Monday and the beam on Tuesday.
Medals in mixed gender events
Changes to the schedule at Tokyo are the result of the International Olympic Committee pledging to make this the "most gender equal" Games and its president Thomas Bach saying they would be "more youthful, more urban and include more women".
It means as well as introducing events such as skateboarding, sport climbing and BMX freestyle, nine new mixed-gender disciplines were added to seven current Olympic sports.
Great Britain took gold in two of them on Saturday - triathlon as well as swimming - while San Marino, who won their first Olympic medal this week with a shooting bronze, sealed their second, a silver in the mixed team trap event.
Poland won the first mixed 4x400m relay on the athletics track, while France claimed the mixed team judo gold medal.