How it unfolded
On a 9.6km out-and-back loop through Vienna's tree-lined Prater park, Kipchoge started at 8:15am in 9-degree weather. Breaking two hours over 42.195km required averaging 2:50 per kilometre. To hold that pace, 41 pacemakers ran in rotating groups of seven, forming an open V-formation ahead of and beside Kipchoge to cut wind resistance, while a lead car projected a laser pace line onto the road to hold the formation's position. Drink handoffs came from support staff riding bicycles alongside. Kipchoge held an almost unwavering split across all 42km and pulled away from his pacemakers in the final 500 metres, crossing the line in 1:59:40. A first attempt two years earlier at Monza, called 'Breaking2,' had fallen short at 2:00:25. Because of the rotating pacemakers and mobile drink support, the run was never eligible as an official world record; his official best at the time was 2:01:39, set in Berlin in 2018.
Why it still matters
This was the first proof that a human being could run a marathon in under two hours. The very fact that it wasn't an official record made the event pose one of modern athletics' central questions all the more sharply — how much of a performance belongs to the athlete, and how much to the shoes, the formation, the lighting and the organization. Four years later, Kelvin Kiptum closed that gap to 35 seconds with an official 2:00:35 in Chicago.