Usain Bolt defied doubters to win gold in the men’s 100 meters on Sunday. Bolt finished the race in an Olympic record of 9.63 seconds, the second fastest time ever behind the 9.58 seconds he ran in 2009. Yohan Blake, Bolt’s Jamaican training partner, won silver with a time of 9.75 seconds. The victory made Bolt, who also won in 2008, the first man to win repeat gold medals in the 100 meters on the track. Later in the games, Bolt will attempt to become the first man repeat wins in both the 100 and 200 meters.