25 February 1964
On 25 February 1964, Cassius Marcellus Clay also known as Muhammad Ali, fought Charles "Sonny" Liston for the heavyweight title in Miami, Florida. Liston tried for a swift knockout, but Ali was too fast to catch. By the 7th round, Liston was too exhausted, had hurt his shoulder, and suffered a cut under his eye. Liston refused to continue the fight, leading to Ali being crowed the heavyweight boxing champion of the world. When Ali was 12 years old, he and a friend went to the Columbia Auditorium to partake in free hot dogs and popcorn available for visitors of the Louisville Home Show. When they had eaten, the boys went back to get their bicycles, only to discover Ali's bicycle had been stolen. Fuming, Ali went to the basement of the Columbia Auditorium to report the crime to police officer Joe Martin, who was also a boxing trainer at the Columbia Gym. When Ali said he wanted to beat up the person who stole his bike, Martin told him that he should probably learn to fight first. A couple of days later Ali began training at Martin's gym. From the very beginning, Ali took his training seriously. He trained six days a week. During schooldays, he woke up in the early hours so that he could go running and then would go workout at the gym in the evening. When Martin's gym closed, Ali would then go and train at another boxing gym.
References

Osenberg, J. (n.d.), 'A Biography of the Famous Boxer', from About.Com: 20th Century History, [online], Available at www.history1900s.about.com [Accessed: 26 January 2011]|Anon, (n.d.), 'Muhammad Ali', from Answers.com, [online], Available at www.answers.com [Accessed:26 January 2011]