Well upsets do occur and this time it was American Venus Williams to succumb to the upsets.
Venus crashes out of Olympics medal race
In her third round match against German Angelique Kerber, Venus could not over power her opponent and crashed out of the Olympic medal race 6-7, 6-7.
Venus, who won a gold in Sydney Olympics 2000, was all set to move forward and win a medal of any sorts.
Venus' crashing out now places onus on the younger Williams, Serna to carry on and win the gold for America. Serena is in her superb form after her fifth Wimbledon title recently. She crusies forward by winning over the 2008 silver medal winner Vera Zvonareva 6-1, 6-0.
As for other ladies, world no.3 and former world no.1 until recently when she crashed out of the Wimbledon Russian Maria Sharapova, the Russian flag bearer in Olympics this year, faces former world number one Kim Clijsters in the quarter finals. Clijsters beat Serbia's Ana Ivanovic 6-3, 6-4.
World no.1 Victoria Azarenka cruises to the quarter finals after she beat Russian Nadia Petrova 7-6, 6-4. She now faces Venus Williams' conqueror Angelique Kerber.