Sifan Hassan of the Netherlands set a new one-hour world record of 18.93km at the Diamond League meeting in Brussels.
Hassan, who is 10,000m and 1500m world champion, pulled away from Kenyan marathon world record holder Brigid Kosgei at the end of the one-hour race.
The 27-year-old’s effort surpassed Dire Tune’s record of 18.517km, set in 2008.
“I’m very happy. When I started, I didn’t feel good,” Hassan said. “But after I found every single minute very easy.
“It was a very strong race and I’m so happy. I never thought I was going to run so far.”
Four-time Olympic champion Mo Farah will attempt to break the men’s one-hour world record on his return to the track at the same meeting later on Friday.