Lewis-Francis burst onto the scene at an early age but did not attend the 2000 Summer Olympics, instead competing at the World Junior Championships, in which he won gold. Lewis-Francis became Britain's top 100 m sprinter after Dwain Chambers was banned for drug use in 2003. He failed to make the final of the 100 m at the 2004 Summer Olympics, but days later ran the final leg of the 4 × 100 m relay, holding off former Olympic champion Maurice Greene, allowing the Great Britain team to narrowly win in a time of 38.07 seconds. The gold medal team consisted of Lewis-Francis, Marlon Devonish, Darren Campbell and Jason Gardener.