2016 Rio Olympics - Tennis - Preliminary - Women's Singles First Round - Olympic Tennis Centre - Rio de Janeiro, Brazil - 07/08/2016. Serena Williams (USA) of USA reacts after winning her match against Daria Gavrilova (AUS) of Australia. REUTERS/Kevin Lamarque

2016 Rio Olympics - Tennis - Preliminary - Women's Singles First Round - Olympic Tennis Centre - Rio de Janeiro, Brazil - 07/08/2016. Serena Williams (USA) of USA in action against Daria Gavrilova (AUS) of Australia. REUTERS/Kevin Lamarque

2016 Rio Olympics - Tennis - Preliminary - Women's Singles First Round - Olympic Tennis Centre - Rio de Janeiro, Brazil - 07/08/2016. Serena Williams (USA) of USA reacts during her match against Daria Gavrilova (AUS) of Australia. REUTERS/Kevin Lamarque

2016 Rio Olympics - Tennis - Preliminary - Women's Singles First Round - Olympic Tennis Centre - Rio de Janeiro, Brazil - 07/08/2016. Serena Williams (USA) of USA in action against Daria Gavrilova (AUS) of Australia. REUTERS/Kevin Lamarque

2016 Rio Olympics - Rowing - Repechage - Men's Single Sculls Repechages - Lagoa Stadium - Rio De Janeiro, Brazil - 07/08/2016. Andrew Peebles (ZIM) of Zimbabwe rows on the course after high winds postponed racing . REUTERS/Carlos Barria

2016 Rio Olympics - Rowing - Repechage - Men's Single Sculls Repechages - Lagoa Stadium - Rio De Janeiro, Brazil - 07/08/2016. Race officials stand by in a boat shortly after competition was postponed due to high winds. REUTERS/Carlos Barria

2016 Rio Olympics - Rowing - Repechage - Men's Single Sculls Repechages - Lagoa Stadium - Rio De Janeiro, Brazil - 07/08/2016. Andrew Peebles (ZIM) of Zimbabwe rows on the course after high winds postponed racing . REUTERS/Carlos Barria

2016 Rio Olympics - Rowing - Repechage - Men's Single Sculls Repechages - Lagoa Stadium - Rio De Janeiro, Brazil - 07/08/2016. Race officials stand by in a boat shortly after competition was postponed due to high winds. REUTERS/Carlos Barria