Anthony Ervin, who tied for the 50m freestyle gold medal at the 2000 Sydney Olympics, stands alone atop the podium in the event 16 years later.
He raced to 21.98 seconds at the 2000 Olympics. In 2016, at the age of 35 and the oldest-ever individual Olympic gold medalist, he clocked 21.40 seconds.
Florent Manaudou of France, who won the event in 2012, was 0.01 seconds behind Ervin for the silver.
Nathan Adrian picked up his second individual bronze medal of the Rio Games, racing to 21.49 and joining Ervin on the podium.