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Chepkoech missed out on a medal at last year's World Championships in London

Muller Anniversary Games Venue: London Stadium Date: 21-22 July Coverage: Live coverage on BBC One and BBC Two, with text commentary on the BBC Sport website and app. Full details

Kenya's Beatrice Chepkoech smashed the 3,000m steeplechase world record on a night of impressive performances at the Diamond League meeting in Monaco.

The 27-year-old ran eight minutes 44.33 seconds to beat the 8:52.78 set by Bahrain's Ruth Jebet two years ago.

On Friday, Olympic champion Jebet was named among more than 100 athletes and coaches facing disciplinary action for alleged doping offences.

"I am so grateful," said new world record holder Chepkoech.

"I said from the beginning, from the first lap, and I was watching the time, and I knew I was going to break the world record."

Once pacemaker Caroline Tuigone dropped out Chepkoech - who was fourth behind Jebet at the 2016 Olympics - maintained a strong pace to beat her previous best over the distance by just over 15 seconds.

Chris O'Hare broke the Scottish record in a 1500m won by Kenya's Timothy Cheruiyot in a world lead of 3:28.41.

O'Hare's Scottish record of 3:32.11 means he moves to sixth on the all-time UK list while fellow Scot Jake Wightman improved his best by 0.21 seconds to 3:33.96.

Rising sprint star Noah Lyles kept his unbeaten record with victory over world champion Ramil Guliyev of Turkey in the 200m.

Lyles, who turned 21 on Wednesday, pulled away from the field as he ran a lifetime best, world lead and meeting record of 19.65secs, which leaves him as the fastest man so far this year over both 100m and 200m.

In the women's 400m, Olympic champion Shaunae Miller-Uibo of the Bahamas improved her personal best and set a new world lead of 48.97secs, holding off the challenge of Bahrain's Salwa Eid Naser.

Miller-Uibo's performance means she becomes the 10th woman in history to go under the 49-second mark.

South African Caster Semenya extended her unbeaten run in the 800m to 38 races with a meeting record of 1:54.60.

It looked like a world record could be on the cards for Semenya after a strong first 200m allowed her pull away from the rest of the field.

But although she comfortably maintained her advantage, Jarmila Kratochvilova's 1:53.28 remained out of her reach.