Jakob Ingebrigtsen produced a fine front-running performance to make history at the Brussels Diamond League meet on Friday (8 September).
The Norwegian, who retained his 5000m world title in Budapest last month after taking silver in the 1500m, benefitted from some excellent pacemaking and Wavelight assistance to break the 2000m world record.
Olympic 1500m champion Ingebrigtsen had not even been born when Hicham El Guerrouj ran 4:44.79 in Berlin in 1999, and the 22-year-old was on his own and on target with one lap to go.
With the crowd inside the King Baudouin Stadium roaring him on, he went clear of the green indicator lights to stop the clock more than a second and a half inside the great Moroccan's previous mark in 4:43.13.
Afterwards Ingebrigtsen said, "It's always fun to break a record. This one qualifies as a world record and not as a world's best. I knew I was able to break this one, but I had some kind of virus 10 days ago and didn't really know how I would be feeling today. However, I felt really good and ran a good race.
"To be honest, this record wasn't a difficult one for me. Sure, when you have to do it alone, it's really tough, but I got great help from the pacemakers. Actually they were able to help me more than I expected."
With it being a seldom-run event, there was a myriad of personal bests in behind with Reynold Cheruiyot taking second in a Kenyan record of 4:48.14.
Australia's Stewart McSweyn ran an Oceania record of 4:48.77 with young Dutchman Niels Laros in fourth place.