Jakob Ingebrigtsen set the first outdoor world record of his career in the little-run 2,000m at the Diamond League meeting in Brussels on Friday.
The women's 200m world champion Shericka Jackson was also in blazing form as she clocked the fourth fastest time in history in 21.48 sec.
Ingebrigtsen, 22, ran 4min 43.13sec to smash a record set in 1999, before he was born, by Moroccan great Hicham El Guerrouj, by more than a second and a half.
The 2,000m is not on the Olympic or World Championships programme, but the Norwegian said: "It's always fun to break a record."
Ingebrigtsen is the reigning Olympic champion in the 1500m and has held the world indoor record at the distance since February 2022 when he ran 3:30.60.
El Guerrouj holds that outdoor record too with a time of 3:26.00 set in July 1998.
Ingebrigtsen ran the fourth fastest ever outdoor 1500m time when he timed 3:27.14 in July but the lost his world title to Britain's Josh Kerr in Budapest in August.
Jackson, a 29-year-old Jamaican, is also chasing a longstanding record. She set the second fastest time in history at the World Championships in Budapest but her time of 21.41sec was still 0.07sec off the world record set by the late Florence Griffith-Joyner at the Seoul Olympics in September 1988.
After her run on Friday, she now owns three of the four fastest women's 200m times in history.
Jackson is due to conclude her summer season at the Diamond League final in Eugene, Oregon in mid-September.
"It has been a good season and I hope to get one more win and to get closer to that record," Jackson said.
es/pb/gj
