Jacob Kiplimo of Uganda has made a mockery of the world half marathon record, smashing the former record by 48 seconds by running 56 minutes 42 seconds in Barcelona.
The 24-year-old reclaimed the record he held from 2021to November 2024 with what he described as a "perfect" race.
"Today everything has been perfect, the course, the weather and of course myself," Kiplimo wrote on Instagram.
The Ugandan made the most of perfect conditions — 13 degrees Celsius with no wind — to become the first athlete to break 57 minutes for the 21.0975km distance.
To emphasise just how astonishing this performance was, previous world record holder Yomif Kejelcha of Ethiopia had broken Kiplimo's previous mark by just a single second in Valencia in November last year.
World Athletics said the 48-second jump was the greatest single improvement on the men’s world half marathon record in history.
Kenyan pair Geoffrey Kamworor (58:44) and Samwe Mailu (59:40) completed the podium.
"It has been the perfect race," Kiplimo told World Athletics.
"Ideal temperature, no wind at all, fantastic circuit — everything went better than expected.
"The pacemaker set the agreed 2:45 pace but 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."
In obliterating the record, the Ugandan two-time world cross country champion and Olympic bronze medallist over 10,000m, also set a world best of 40:07 for 15km.
Not since Eliud Kipchoge broke the marathon world record by 78 seconds in 2018 has a men's distance record been so comprehensively bettered.
Letesenbet Gidey broke the women's half marathon record by 70 seconds in Valencia in 2011 in a mixed-start race, while Peres Jepchirchir broke the women's only marathon world record by 45 seconds in London in 2024.
The breakdown of Kiplimo's performance is just as astonishing.
Kiplimo averaged 22.3kmh, or 2:41 per kilometre. That equates to 13:26 for your local parkrun, four times back-to-back or 26:53 for 10km.
Incredibly, the Ugandan's personal best for 10km on the track is 26:33.93.
Excitingly, Kiplimo will make his marathon debut in London on April 27 where, given similar conditions, he would back himself to challenge the late Kelvin Kiptum's world record of 2:00:35.
"I won't compete any more until my marathon debut in London on 27 April," Kiplimo said, adding on Instagram that this result makes him "confident" of doing well there.
In the women's race, former world record-holder Joyciline Jepkosgei (Kenya) claimed victory in a personal best time and course record of 1:04:13, with compatriot Gladys Chepkurui in second (1:06:23) and Alemtsehay Zerihun (1:08:19) third.
