(CNN) -- Roger Federer and the Williams sisters Serena and Venus cruised into the fourth round of their respective draws in the joint ATP and WTA tournament at Key Biscayne in Florida.
Serena shows her frustration but breezed past Peng Shuai in straight sets.
World number two Federer is playing catch-up with top-ranked Rafael Nadal but showed signs of his best form with a 6-4 6-1 victory over Nicolas Kiefer, his 11th straight win over the German.
Federer, a two-time winner at the prestigious tournament in Florida, will next play American Taylor Dent, who put out 15th seed Tommy Robredo of Spain in straight sets.
Dent is returning to the circuit after two surgeries for back injuries and Federer told the official tournament Web site www.sonyericssonopen.com that it was great to have him back.
"He was always a dangerous player on tour because he was aggressive, offensive and kind of making the match decide on a couple of passing shots here and there.
"It's going to be interesting for me to see how he plays. I actually never played him, so I can't compare before and after injury. I'm looking forward to a good match."
Reigning Australian Open champion Serena Williams had little trouble in beating China's Peng Shuai 7-5 6-2 while her fifth-seeded sister Venus saw off Germany's Anna-Lena Groenefeld 7-5 6-3.
The draw is opening up for the all-conquering duo who could meet in the semifinal of the $9million tournament.
Serena was under pressure from Dinara Safina for the world number one spot, but she went out to unseeded Australian Samantha Stosur 6-1 6-4.
Serbian pair Ana Ivanovic and Jelena Jankovc also exited the women's tournament at the weekend.