Make it four gold medals for swimmer Caeleb Dressel at the Tokyo Olympics.
Dressel cruised to a relatively easy victory in the frenetic dash from one end of the pool to the other, touching in an Olympic record of 21.07 seconds.
France's Florent Manaudou repeated as the Olympic silver medalist in 21.57, and Brazil's Bruno Fratus claimed the bronze in 21.57, edging out American Michael Andrew for the final spot on the podium.
Dressel has one more shot at a gold in the 4x100 medley relay, an event the United States has never lost at the Olympics.