Complex sentence: In 2003, Dibaba won the 5000 metres in a sprint finish against Marta Dominguez of Spain and Edith Masai of Kenya, becoming the youngest athlete to win an individual gold medal at the World Championships.
Split into simpler sentences: In 2003, Tirunesh won the 5000 m in a sprint finish against Marta Dominguez of Spain and Edith Masai of Kenya. She became the youngest athlete ever to win an individual gold medal at the World Championships.