As the king of sprinting and the biggest global star at the Rio Games, Usain Bolt of Jamaica held aloft his index finger, signaling that he was No. 1, during introductions Sunday night as a smitten crowd chanted his name.

Then Bolt proved it again, winning the 100 meters in 9.81 seconds, a coronation that secured his place as the greatest sprinter of all time. He is the only man or woman to win the Olympic 100 three times, which he accomplished at three consecutive Games.

His main rival, Justi