Michael Phelps waves to the audience after winning his 23rd Olympic gold medal. [Photo/Agencies]

The USA's two victories on Saturday gave them 16 out of a possible 32 swimming gold medals here.

Blume won Denmark's first gold medal in any event at the Rio Games by storming to victory in the women's 50m freestyle.

The 22-year-old finished in 24.07 seconds, just two hundredths of a second ahead of Simone Manuel of the US. Belarus swimmer Aliaksandra Herasimenia took bronze in 24.11 seconds.

Blume had never previously claimed an Olympic medal, despite winning three world championship titles.

Her time fell just short of the Olympic record of 24.05 seconds set by Dutch swimmer Ranomi Kromowidjojo at the London 2012 Games.

Manuel became the first Afro-American individual swimming gold medallist when she won the 100m freestyle on Thursday. The 20-year-old was also part of the USA's 4x100m freestyle relay team that claimed the silver medal on August 6.

Paltrinieri, 21, coasted to victory in the men's 1500m freestyle, touching the wall in 14 minutes, 34.57 seconds, 4.91 seconds ahead of the USA's Connor Jaeger. Paltrinieri's fellow Italian Gabriele Detti took the bronze medal in 14:40.86.

Paltrinieri, the 1500m gold medallist at last year's world championships in Russia, led from the outset and swam under world record pace for much of the race before easing off in the final laps.

China's world record holder and defending champion Sun Yang failed to qualify for the 1500m final.