Bolt shockingly jumped the gun – and knew right then that he had made the biggest mistake of his career.
Blake held his nerve though and went on to recover from a poor start to crown himself world champion with a 9.92 seconds run in a strong headwind.
American Walter Dix finished second in 10.08 and Kim Collins of St Kitts and Nevis taking the bronze in 10.09.
Bolt was seen as the favourite to take the gold medal following the withdrawal of Tyson Gay and Asafa Powell.
The Jamaican will now look to the 200m and 4x100m for redemption.