USA swimmer Anthony Ervin clinched his second medal in Rio when he won the 50m freestyle final in 21.40 secnds.
Ervin had already won a gold in the 4 x 100m relay, though he never actually swam in the final, but had earlier helped the team through in the heats.
At the age of 35, this made him the oldest individual Olympic gold medal winner in swimming, taking the record American legend Michael Phelps, who took five golds and a silver away from Rio.