Full coverage: 2016 Rio Olympics
Begin with swimming, and the final of the women's 100m butterfly. China qualified two competitors for this event, Lu Ying and Chen Xinyi. But they faced a tough challenge against the heavy favorite, Sarah Sjostrom, who is a three-time world champion in this event.
Chen and Lu fall behind after the first 50 meters, and finally finish in fourth and fifth.
Meanwhile, Sjostrom dominates the race and touches the wall first in 55.48 seconds, a new world record. Canada's Penny Oleksiak comes in second.
Sarah Sjostrom takes women's 100m butterfly
Briton finishes in 57.13 seconds to break own world record
In the men's 100-meter breaststroke, Adam Peaty of Great Britain again breaks the world record he set in the semi-final. Peaty finishes within 57.13 seconds, 1.56 seconds ahead of second placed South African Cameron Van der Burgh.
In the women's 400-meter freestyle, American swimmer Katie Ledecky is clear favorite and leads most of the race. She finishes within three minutes, 56.46 seconds, creating a new world record. Jazz Carlin of Great Britain comes seconds.