The women's 100m has been billed as the biggest draw of the Tokyo 2020 Olympics - and the heats get under way on Friday.
Dina Asher-Smith is bidding to become the first British woman to win an individual sprint gold at a Games and will be in one of the seven first round heats between 03:40-04:30 BST.
The semi-final will take place on Saturday at 11:15 BST, with the final starting later that day at 13:50 BST.
Asher-Smith, 25, is the fastest British woman in history, a world and four-time European champion and was an Olympic bronze medallist in the 4x100m relay in Rio.
But she's up against Jamaican duo Shelly-Ann Fraser-Pryce and Elaine Thompson-Herah, who between them have won the past three Olympic 100m titles.
Fraser-Pryce, 34 - the 2008 and 2012 champion - ran a time of 10.63 seconds at a national trials warm-up event in June to become the fastest woman alive and set the bar going into the Games.
Thompson-Herah, 29, will be looking to defend her 2016 gold medal.
Then there's Nigeria's Blessing Okagbare, who ran her fastest time since 2018 with 10.89secs on 6 July.
So it's no wonder three-time Olympic sprint gold medallist Veronica Campbell-Brown believes the women's 100m will be a "fierce battle from the first round all the way to the final".
"No doubt the women's 100m is the most anticipated race in Tokyo," said Campbell-Brown.
"It is so loaded with talent and it's going to come down to the ones [who are] able to handle the pressure - who can execute and can run the race of their life, because I really think that it will take 10.70 seconds, if not 10.60, to win that 100 meters.
"Shelly-Ann has gone 10.63secs so far and so no doubt she may be the most hunted."
Campbell-Brown added Asher-Smith's performance will be enhanced as she is competing against two other athletes at the top of their game.
"Elaine and Shelly-Ann will actually help Dina run a better race because going into a race with Shelly-Ann and Elaine, you have to know that you have to bring your A-game," she said.
"Dina and a lot of the other ladies are trying to make their first gold medal. So with all the confidence and all the hard work they have put in it, I'm sure that they are ready to explode and can't wait to just go there and get started."
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The men's 100m event then begins on Saturday - with the preliminary round starting at 03:35 BST and a total of seven heats in the first round, which begins at 11:45 BST. The semi-final will take place on Sunday starting at 11:15 BST and the final will begin at 13.50 BST the same day.
A new Olympic champion will be crowned after the retirement of superstar Usain Bolt, who won gold at the 2008, 2012 and 2016 Games.
The clear favourite is American Trayvon Bromell as he clocked a time of 9.77secs in July -the fastest time in 2021 and the seventh fastest of all-time.