American Keni Harrison broke a 28-year-old world record in the 100m hurdles, clocking 12.20 seconds at the London Anniversary Games.
Harrison, 23, was already the fastest woman in the world this year, but will not be at next month’s Olympics after finishing only sixth in the US trials.
The previous world record of 12.21 had stood since 1988 and was held by Yordanka Donkova of Bulgaria.
Britain’s Tiffany Porter came sixth and Jessica Ennis-Hill last.
“After not making the Olympic team I wanted to come out here and show what I could have done,” an emotional Harrison said.
“The US team is the hardest to make, our country wants the top three from the trials and I was not that person. The pressure got to me on the day. I wish I could re-do that day.
“I came out here with a lot of vengeance. I knew I had it in me.
“I’ve still got a lot left in me, I’m definitely going to try and drop that time this season.”
Harrison has run six of the seven fastest times this year, and two of the four fastest ever.
Defending Olympic champion Sally Pearson will also miss out in Rio after tearing a hamstring last month.