Eliud Kipchoge ran the quickest recorded marathon on Saturday, crossing the line at the Monza Formula One track in two hours and 25 seconds but missing out on an ambitious attempt to break the two-hour barrier.
The 32-year-old's time smashed the official mark of 2:02:57 set by fellow Kenyan Dennis Kimetto in Berlin in 2014 but will not enter the record books largely due to a non-compliant system of pacemaking.
"The is not the end of the attempt of runners on two hours," the Olympic champion said after the race, likening the challenge to climbing a tree. "When you step on the branches... immediately you go to the next one."
Kipchoge rated it as the finest performance in a career that includes a gold medal at the Rio Games last year and a personal best official time of 2:03:05, the third-fastest in history.
"This journey has been good, it has been hard, it has been seven months hard preparation. It has been history in the world of sport," he added.
Kipchoge and the only other competitors, Eritrean Zersenay Tadese and Ethiopian Lelisa Desisa, ran behind an arrow-head formation of pacemakers, to reduce drag, and a car beaming a green line on the road behind it to show the required speed for the sub-two hour target.