Eliud Kipchoge has become the first marathon runner to break the two-hour barrier, recording a time of 1 hour 59 minutes 40 seconds in Vienna.
He had previously pushed the mark close in a similar attempt at the Monza Formula One racetrack near MIlan in 2017.
Kipchoge ran 2:00:25 on that occasion, but added extra pacemakers and allowed fans to line the streets for this attempt, as he made sporting history in Austria.
Who is Kipchoge?
Kipchoge is perhaps the best candidate in the world to attempt such a historic achievement in breaking the two-hour barrier for the marathon.
A four-time champion of the London marathon, having won the last two editions, as well as a two-time winner in Berlin and a solitary victory in Chicago to go with his Olympic gold medal.
What is the 1:59 challenge?
Ineos have sponsored the event, which will take place around the 4.3km stretch on the Prater Hauptallee in Vienna, Austria, with 4.4 laps required to complete the marathon distance.
Elevation will remain comfortably flat, though it will fluctuate between 1.8 and 4.0 metres. One request of Kipchoge since Nike Breaking2 was to involve fans, meaning the route will be lined by spectators in order to provide him with support.