By Agence France-Presse
Backed by a small army of scientists and helped by an ever-changing battalion of pacesetters, Kipchoge set out to complete the classic marathon distance of 26.2 miles (42.195 kilometres) in 1hr 59min 59 sec or faster on a fixed loop at the Monza National Autodrome racing circuit in Italy.
In his pursuit of sporting immortality, Kipchoge had to set a ferocious pace of 4min 34sec per mile -- seven seconds quicker than the pace of the existing world record of 2:02:57 set by Dennis Kimetto of Kenya at the 2014 Berlin Marathon.
Requiring the sort of evolutionary leap against the clock that is usually only achieved over decades, Kipchoge started in promising fashion.
Despite being a second over the target time after five kilometres, Kipchoge was clocked at five seconds under after 10 then 15 km, and was still two seconds inside the target at the 25 km mark.
But over the remaining third of the race, which began at 0545 local time (0345 GMT) in slightly humid conditions, Kipchoge steadily began to fall behind pace.
He was clocked at over six seconds over the required pace at the 35km mark and, over the remaining kilometres, began to steadily trail his pacesetters before finishing just 25 seconds over the target.