Rio de Janeiro: Defending Olympic champion and world number one Serena Williams suffered a shock third round defeat at the hands of Ukraine`s Elina Svitolina on Wednesday at Olympic Tennis Centre, Rio de Janeiro.
Serena, winner of 22 Grand Slam singles title, failed to produced her routine game and lost the match in straight sets, 6-4, 4-3 in one hour and 12 minutes.
Her elder sister Venus had already crashed out of the singles competition. Besides, the the Williams sisters suffered their first defeat as a doubles team at Olympics yesterday.
Svitolina, ranked 20 in the world, will play former world number one two-time Wimbledon champion Petra Kvitova of Czech Republic in tomorrow's quarter-final.
Kvitova is a also a time-time quarter-finalist at Olympics.
