Three of the top four seeds for the men's singles are through to the semi-finals of the Olympic tennis tournament.
Wimbledon champion Roger Federer will play the 8th seeded Argentine Juan Martin del Potro and the second seed Novak Djokovic will play third seed Andy Murray.
In the semi-finals of the women's singles, top seed Victoria Azarenka will play Wimbledon champion Serena Williams.
In an all-Russian affair, third-seed Maria Sharapova will play Maria Kirilenko.
