Williams sisters advance at Sony Open

MIAMI, March 21 (UPI) -- Serena and Venus Williams both reached the third round of the Sony Open Thursday, using very different methods to do so.

Serena Williams, the No. 1 seed and winner of this event five times, had no trouble in getting past Flavia Pennetta to set up a third-round matchup with Ayumi Morita.

Venus Williams, seeded 19th, outdueled Kimiko Date-Krumm 7-6 (7-3), 3-6, 6-4. The older of the Williams sisters will next meet Magdalena Rybarikova, who surprised No. 27 seed Mona Barthel 6-3, 7-6 (7-5).

Fourth-seeded Agnieszka Radwanska also advanced by overcoming Su-Wei Hsieh 6-3, 6-2. Radwanska won this tournament a year ago, defeating Maria Sharapova in the championship match.

In other second-round matches Thursday Australian Open runner-up Li Na defeated Kiki Bertens 6-3, 6-1 and former Wimbledon champ Petra Kvitova ousted Peng Shuai 5-7, 6-2, 6-2.

Caroline Wozniacki rallied for a 5-7, 6-3, 6-3 decision over Karolina Pliskova and Dominika Cibulkova won over Kristina Mladenovic, 6-2, 6-3.

Also advancing were Sloane Stephens, Garbine Muguruza, Ajla Tomljanovic and Kirsten Flipkens.