The last stage of Tour of Rwanda in Kigali, site of this year's cycling world championships, was abandoned on Sunday after rain made the roads unsafe.
The decision was taken by officials from cycling's governing body, the UCI, organisers said.
"Due to unforeseen weather conditions that made the roads slippery, the president of the UCI jury decided to stop the last stage of the Tour of Rwanda with one lap remaining," said the organisers.
The Road World Championships are due to be held in Africa for the first time in Kigali from September 21-28.
The early end to the race gave Fabien Doubey, a 31-year-old Frenchman who rides for with TotalEnergies his first professional victory. He finished six seconds ahead of Eritrean Henok Mulubrhan