• However, guided by trackside lights illustrating world record pace, he came home in 12 minutes 35.36 seconds.
Uganda's Joshua Cheptegei produced an astonishing run in Monaco to break the 16-year-old 5,000m world record by almost two seconds.
The 23-year-old, who won the 10,000m world title in Doha last year, had promised he would take a shot at the time but success seemed unlikely.
However, guided by trackside lights illustrating world record pace, he came home in 12 minutes 35.36 seconds.
The previous mark, set by Ethiopian great Kenenisa Bekele, was 12:37.35.
Remarkably it is Cheptegei's second world record in Monaco this year, despite the season being badly disrupted by the coronavirus pandemic.
He broke the 5km road world record in the principality in February.
He was not the only athlete to make light of the lack of competitive action to post impressive times.
Britain's Laura Muir broke Dame Kelly Holmes' 21-year-old British 1,000m record with a time of 2:30.82, in a race won by Kenya's Olympic champion Faith Kipyegon.
Norwegian world champion Karsten Warholm turned the 400m hurdles into a solo time trial, breaking Kevin Young's 1992 meeting record in 47.10 and serving notice of his intention to do the same to the American's long-standing world mark.
Scotland's Jake Wightman took more than two seconds off his 1500m personal best, coming home in 3:29.47. It earned him a creditable third behind Timothy Cheruiyot and Jakob Ingebrigtsen, world and European champion respectively, and moved him up to second in the British all-time standings.
Kenyan world champion Hellen Obiri took a comfortable win in the 5,000m, with rival Sifan Hassan stepping out of the race with a couple of laps to go and Britain's Laura Weightman claiming a personal best in third.
Great Britain's Andrew Pozzi has re-started the year in electric form. The 28-year-old, who came within three hundredths of his personal best in Finland on Tuesday, duly matched it with a time of 13.14 seconds to claim a narrow second place behind Spain's Rio 2016 silver medallist Orlando Ortega in the 110m hurdles.