15 greatest upsets in Summer Olympic history

9. 1960: Barefoot runner wins marathon

Nowadays, people spend hundreds of dollars on equipment to make sure they can finish a marathon. In 1960, an Ethiopian runner ran the biggest marathon in the world without even having shoes on, and he actually won the event. It was one of the greatest feats in Olympic history, and an incredible upset.

Abebe Bikila was added to the Ethiopian team at the last minute, as he replace Wami Biratu, who was seriously ill. When he arrived in Paris, Adidas, the shoe sponsor for the Olympics, did not have many shoes left. He could not find ones that were comfortable, so he decided to run without any. Incredibly, he finished in 2 hours and 15 seconds, becoming the first Sub-Saharan African to win a gold medal.

In 1964, Bikila became the first person to win two gold medals in the event, as he won in Tokyo despite not being expected to compete. In fact, Bikila finished the marathon in a new Olympic record time of 2:12:11.2, which was over four minutes faster than the silver medal winner, Basil Heatley of Great Britain. This time, however, Bikila wore shoes and socks.

Bikila ran again in 1968 in Mexico City, but he injured his right knee at the 17km mark. His running partner, Mamo Wolde won the event.

Next: 8. 1976: East German doping can't keep the U.S. from gold