Last Updated: 12/08/08 3:22pm
Tough serve: Venus Williams
Venus and Serena Williams, together with world number one Jelena Jankovic, advanced to the third round of the women's singles in Beijing on Tuesday.
Serbia's Jankovic, also the Olympics top seed in the absence through injury of compatriot Ana Ivanovic, beat Ukraine's Alona Bondarenko 7-5 6-1.
Jankovic improved as the match progressed and broke Bondarenko three times in the second set.
However, Jankovic, who was wearing a strapping on her troublesome right calf, did not look completely at ease around the court.
The Williams sisters - who could potentially meet in the final - earlier confirmed themselves to be among the favourites for gold by both taking straight sets wins.
Serena took just 44 minutes to dispatch Australia's Samantha Stosur 6-2 6-0, the fourth seed reeling off the last 10 games to love.
"It was clean," said Serena, who missed the 2004 Games in Athens through injury. "My way of improving on it is to keep it up."
Her third-round opponent is France's Alize Cornet, the 15th overcoming a vociferous home crowd in defeating China's Peng Shuai 6-2 6-2.
Meanwhile, Serena's sister Venus had a similarly easy passage, the seventh seed beating the Czech Republic's Iveta Benesova 6-1 6-4.
"I'm not sure that I faced any breakpoints today, so that's really good," she said. "That's good for me going on in the later rounds, that I'm tough on my serve.
"I definitely feel more confident with every match that passes. That's what winning does."
Russian sixth seed Dinara Safina progressed with a 7-6 (7-3) 6-1 victory over Spain's Maria Jose Martinez Sanchez, while Slovakia's Dominika Cibulkova beat Bulgaria's Tsvetana Pironkova 6-2 6-2.
However, seeds did fall in morning play, with 10th seed Daniela Hantuchova of Slovakia going down 6-1 6-3 to Denmark's Caroline Wozniacki.
Eighth seed Agnieszka Radwanska also crashed out, the Pole losing 6-3 7-6 (8-6) to Italy's Francesca Schiavone.
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