Uganda's Jacob Kiplimo broke the world half marathon record with a time of 56 minutes and 41 seconds in Barcelona, 49 seconds faster than the previous mark set by Ethiopia's Yomif Kejelcha in October.
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.
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 found myself full of energy and decided to inject a brisker rhythm from the third kilometre, but I never imagined to perform under the 57-minute barrier, that's astonishing.
Kiplimo broke the 57-minute barrier with an astonishing run in Barcelona.
