Kenya's Beatrice Chepkoech broke the 5 kilometres world record on Sunday, finishing in a time of 14 minutes 43 seconds round the streets of Monaco to clip one second off the old mark.
The 29-year-old Chepkoech, who also holds the world record in the 3,000 metres steeplechase, battled windy conditions with assistance from her pacemaker Luuk Maas.
"I'm so happy. Even though there was a lot of wind, I managed to run right on pace," Chepkoech said.
"In the end, my pacemaker told me 'we can do it, let's push it'. I'm really happy with this world record."
Uganda's Joshua Cheptegei, the 10,000 metres world champion, won the men's race in a time of 13 minutes and 14 seconds.