Joshua Cheptegei smashed the 5k world record in Monaco on Sunday.
The Ugandan ran the streets of the principality in 12:51, taking a massive 27 seconds off the previous record which was held by Rhonex Kipruto. 20-year-old Kipruto had only set the previous best time last month in Valencia en route to setting the 10k world record.
"Wow, this is a really great," 23-year-old Cheptegei told World Athletics.
I had sub 13 minutes in my mind today so when my legs felt good during the race I decided to really go for it.
To take this many seconds off the record makes me very happy and is a great first test for me in an important season.
Cheptegei, who won the 10,000m at World Championships last year, appeared to be wearing the Nike Vaporfly Next%, the controversial shoes which many have used while setting world records in recent times.
France's Jimmy Gressier finished second in 13:18, setting a new European record, while Great Britain's Nick Goolab was third in 13:27
Photo by Sam Barnes/Sportsfile