World Athletics Championships: New-look GB team wins 4x100m relay bronze

 A new-look Great Britain quartet won 4x100m bronze in the final race of day nine of the World Championships.

With Jona Efoloko, 22, preferred to Adam Gemili on the opening leg and Reece Prescod on the anchor, Britain held off Jamaica to ensure a medal.

Canada exploited a slack final changeover from the United States to take gold ahead of their neighbour.

A mystery leg injury to Dina Asher-Smith cost Great Britain's women a shot at a medal in the 4x100m relay.

The 26-year-old, who finished fourth in the 100m and won bronze over 200m during a hectic schedule in Oregon, hobbled through the final 15m of her third leg.

Great Britain, who had been third in the race, slipped back to eighth as she slowed. Daryll Neita ran the fastest split of anyone in the race - 9.57 seconds - on the anchor leg, but it was only enough to regain sixth.

"I feel confused because I felt fine coming in, but when I was going round the bend my legs just stopped corresponding with me," Asher-Smith told BBC Sport.

"I hope it is nothing serious as I have a lot more races to do this year. I feel awful because we were running well."

Asher-Smith has been named in the England team for the Commonwealth Games, which begins next week, and has three titles to defend at August's European Championships in Munich.

At the front of the race, the United States claimed a memorable victory over an all-star Jamaican team.

Shelly-Ann Fraser-Pryce, Shericka Jackson and Elaine Thompson-Herah, who filled the podium in the 100m, were part of the Jamaica quartet attempting to defend their 2019 title.

But excellent legs from Melissa Jefferson and Abby Steiner gave the Americans an advantage that survived Jackson's surge for the line by four hundredths of a second.

Germany took bronze.