|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.|
Dina Asher-Smith returned as Great Britain set a new national record to win their heat and reach the women’s 4x100m relay final on Friday.
The 200m world champion ran the third leg as the British quartet finished ahead of the USA and Jamaica in 41.55 seconds.
Asher-Smith, who tore her hamstring in July, pulled out of the Olympic 200m after failing to make the 100m final.
Asha Philip, Imani-Lara Lansiquot and Daryll Neita completed the GB team.
“There was never any doubt in my mind that I’d be lining up here today because the relay’s really important, we got a bronze medal in Rio,” Asher-Smith told BBC Sport.
“These ladies are in great shape, they’re incredibly talented, so I knew I had to rest up and get ready for the team event. I’ve been training hard to get ready.”
Individual women’s 100m gold medallist Elaine Thompson-Herah and silver medallist Shelly-Ann Fraser-Pryce did not run for Jamaica but both are likely to return for Friday’s final.