On Sunday, Dressel swam the men's 50m freestyle event in 21.07 seconds,  breaking the Olympic record set by Brazil's Cesar Cielo in 2008. He swam in the men's 4x100m relay, setting a new world record of 3 minutes 26.78 seconds. The previous record was 3 minutes 27.28 seconds team USA set at the 2009 Rome world championships.

The first of Dressel's 5 gold medals came on the first Sunday of Olympic competition, when he swam the fastest opening leg in the men's 4x100m free relay. On Thursday,  he set an Olympic record of 47.02 seconds in 100m freestyle. Saturday's 100m butterfly brought Dressel the world record of 49.45 seconds.

Quach Thi Lan trains in Tokyo before the official competition. (Photo: Vietnam Sports Delegation/VNA)

On Saturday, the 8th official competition day of the Games, Vietnamese athlete Quach Thi Lan performed excellently, advancing to the semi-finals. She ran the women's 400m hurdles in 55.71seconds. Lan is the second Vietnamese athlete to qualify for the Olympics after Vu Thi Huong in Beijing 2008, but the first Vietnamese athlete to enter the semifinals.

On Monday, Lan will compete with 23 other athletes for the top 8 positions in the final.