1 MEN'S 200M FREE

Aug 9, 9.21am (Singapore time)

Enigmatic Chinese swimmer Sun Yang is hard to beat and he is the defending Olympic champion in the 400m and 1,500m races. But in the 200m, he faces a stiff challenge from British 20-year-old James Guy, who made his mark when he out-touched Sun by 0.06sec at last year's World Championships.

2 WOMEN'S 200M FREE

Aug 10, 9.19am

American teenage star Katie Ledecky is the current world record holder for the 400m, 800m and 1,500m freestyle events. Can the 19-year-old prodigy, the youngest swimmer in the US contingent, be the first swimmer since 1968 to win the 200m, 400m and 800m events in a single Olympics? Ledecky will have to beat Sweden's Sarah Sjostrom, who has clocked the fastest time in the 200m this year.

3 WOMEN'S 100M FREE

Aug 12, 10.18am

Sibling rivalry will feature in Brazil. Australian Cate Campbell broke the world record this year but younger sister Bronte, the 50m and 100m world champion, will be eager to reassert her dominance in sprints.

4 MEN'S 100M FLY

Aug 13, 9.12am

Michael Phelps leads a stacked field in this event on his Olympic swan-song. The defending champion is set for a showdown with Singapore's Joseph Schooling, Hungary's Laszlo Cseh - who has clocked the world's fastest time this year - and South Africa's reigning world champion Chad le Clos.

5 MEN'S 50M FREE

Aug 13, 9.44am

Entered in just one event, French sprinter Florent Manaudou's Olympic Games campaign will be over in less than half a minute. The defending champion, world champion and world's fastest sprinter this year can reinforce his status as the 50m king if he fends off rivals Cameron McEvoy of Australia and Nathan Adrian of USA.