Usain Bolt crosses the finish line for Jamaica during the 4x100m relay heats at the World Championships in London on Saturday. Jewel Samad / AFP
Usain Bolt crosses the finish line for Jamaica during the 4x100m relay heats at the World Championships in London on Saturday. Jewel Samad / AFP
Usain Bolt on course for 15th world gold as Jamiaca reach 4x100m relay final
The 100m and 200m world record holder will race for the final time at a major championships on Saturday evening.
