Mo Farah broke the world record for the distance run in an hour at Friday's Diamond League meeting in Brussels.
The British long-distance runner – a four-time Olympic gold medallist – covered 21,330 metres in 60 minutes, beating the previous best of 21,285m set by Haile Gebrselassie in 2007.
In his first attempt at breaking the record, Farah stepped things up after finding himself around 10 metres behind Gebrselassie's pace at the midway point.
Bashir Abdi overtook Farah with five minutes remaining but the 37-year-old powered back in the final 60 seconds to claim his first world record.
Farah was competing for the first time since October's Chicago Marathon and is now preparing for the 10,000m event at next year's rearranged Olympic Games in Tokyo.
"That's incredible. I'm very happy to break the world record today," he said in an on-track interview.
"Me and Bashir Abdi worked together. I'm so pleased for him and for myself and what an amazing way to do it and show the people what is possible.
"I feel tired but at the same time in the middle part of the race we had to work hard.
"I wasn't sure what we were doing and had to help each other and get through it and it's nice to break a world record."
Meanwhile, Sifan Hassan set a new best distance of 18,930m in the women's equivalent event, breaking the record of 18,517m held by Dire Tune since 2008.