Top-seeded Serena Williams and No 2 Dinara Safina made short work of their second-round opponents on Tuesday to move into the Sydney International quarterfinals.
Williams, who was stretched to three sets and saved four match points in her opening match against Samantha Stosur of Australia, beat Sara Errani of Italy 6-1, 6-2 in 50 minutes on Tuesday.
Her win at Ken Rosewall Arena, the center court at the Olympic Park Tennis Centre, came moments after Safina finished off a 6-3, 6-0 win over fellow Russian Vera Dushevina in just over an hour on Court 1.
Errani was in trouble from the outset, challenging two line calls within eight minutes of the first set _ and both went against her. Errani consulted with her coach after losing a third straight game and although she rallied at the beginning of the second set, the Italian seemed to lose her focus.
Williams said she was much more comfortable with her game on Tuesday.
"I still think I can improve on some things, and that's what I want to do," Williams said. "I don't want to peak too soon. I just want to stay level for the whole season."
Four other seeded players in the women's draw at the joint ATP-WTA tournament also advanced on Tuesday.