Kendra Harrison breaks 100m hurdles world record

Harrison, who missed out on a spot in the USA's team for the Rio Olympics after finishing sixth at the US Olympic trials, ran 12.20 as she demolished the field in London.

After delivering a silky smooth performance to win, the clock initially showed a modest 12.58 seconds.

However, it was quickly corrected to 12.20, one hundredth of a second faster than the mark set by Bulgaria's Yordanka Donkova in 1988 - four years before Harrison was born.

Brianna Rollins (12.57), Kristi Castlin (12.59) and Ali Nia (12.63), all Rio-bound after finishing 1-2-3 in the US trials, finished in the same order, behind Harrison on Friday.

"Not making the Olympic team I was really upset and wanted to come here and show what I could have done," said the 23-year-old after her exploits.

"I had vengeance on my mind and wanted to show the girls what I had.

"I trained so hard for his moment. Good luck to the girls running in Rio, but I am just shocked now."