On Day Five of the championship, with $20 million of prize money up for the grabs, former world No 1 Maria Sharapova (5) from Russia knocked out her compatriot Yelena Vesnina in straight sets, 6-3, 6-0.
Russia's Yelena Dementyeva also enjoyed an easy straight sets victory as she glided past Shahar Peer (17) of Israel 6-2, 6-0. She will face Sharapova in the next round.
In the men's singles, two Russian players enjoyed straight sets victories as Mikhail Yuzhny (14) defeated Ivo Karlovic (20) from Croatia 6-2, 6-4, 6-2 and Nikolai Davydenko (4) overcame Marc Gicquel of France 6-3, 6-2, 6-3.
Russia's Igor Andreyev (31) quit the tournament after losing to Richard Gasquet (8) of France, 3-6, 2-6, 6-4, 4-6.
Davydenko and Yuzhny will now play each other for a quarterfinal spot. They have previously met on the court three times, Davydenko winning all three encounters.