200 Jamaicans , three Americans lead field in women 's 200 final . Female boxers square off in third -ever semifinals . Decathlon begins with 200 events , including 500 meters . Race starts at 10:44 a.m. London time ( 5:44 ET ) Wagner-Augustin meets Australia in men 's basketball quarterfinals .
200 Jamaicans , three Americans lead field in women 's 200 final . Female boxers square off in third -ever semifinals . Decathlon begins with 200 events , including 500 meters . Wagner-Augustin meets Australia in men 's basketball quarterfinals .