Faith Kipyegon on Wednesday evening clocked a stunning 3:50.37 to miss Ethiopian Genzebe Dibaba's world record by three tenths of a second (0.3secs.) in the women's 1500m at the Monaco Diamond League.
American Allie Wilson led through 400m in 59.89 and 800m in 2:01.64 before Jamaica's Adelle Tracey took over to keep the pace as hard as possible.
Kipyegon ran by herself for the last 600 meters after pacers shed, aided by lights along the track showing her the world record pace.
Crossing the finish line, in 3:50.37 Kipyegon set a new Personal Best, a National Record as well as set the second fastest time in history.
"I have been chasing the time for quite some time, but I am happy with the personal best," Kipyegon said, according to organizers. "It seems I did not give all, but I tried hard. I knew this was the best place to get the world record, but I am so disappointed I lost it in the last meters. I hope for the best next time."
Kipyegon, a 28-year-old mom, owns two Olympic 1500m gold medals and two world 1500m titles.
Noah Lyles won a men's 200m showdown with the ninth-best time ever at a Diamond League meet in Monaco.