Uganda’s Jacob Kiplimo (24) broke the world half-marathon record with a time of 56 minutes and 41 seconds in Barcelona on Sunday, 49 seconds faster than the previous mark set by Ethiopia's Yomif Kejelcha in October.
Twice world cross country champion Kiplimo's run was the greatest single improvement on the men's half-marathon record, World Athletics said on its website.
"I am very excited about what I did today," said Kiplimo, who made his Olympic debut in the 5,000m in Rio when he was just 15.
"I started strong, I wanted to have a great race, but I didn’t expect to break the world record.
"As the kilometres passed and I saw that I was going at record pace, I told myself that I had to maintain that pace no matter what it took."
Japan’s Toshikazu Yamanishi broke the men's 20 km race walk world record earlier on Sunday, clocking one hour, 16 minutes and 10 seconds in Kobe to beat the mark set by his compatriot Yusuke Suzuki in 2015.