Mason, OH ( - Reigning U.S. Open champion Serena Williams, French Open runner-up Simona Halep and Roland Garros titlist Maria Sharapova posted third-round victories Thursday at the $2.5 million Western & Southern Open tennis event.

The world No. 1 Williams blew past 13th-seeded Italian Flavia Pennetta 6-2, 6-2 on the hardcourts at Lindner Family Tennis Center.

The 17-time Grand Slam titlist Williams was last year's Western & Southern Open runner-up to Victoria Azarenka, who lost to the American great in the last two U.S. Open finals.

Williams' quarterfinal opponent will be eighth-seeded former world No. 1 Jelena Jankovic, who got past American Sloane Stephens 7-6 (7-4), 6-4 on Day 4. The Serbian Jankovic titled here in 2009 and was the runner-up in 2011.

Williams is 9-4 lifetime against Jankovic, including a win in Dubai earlier this season.

Meanwhile, the world No. 2 Romanian star Halep humbled 16th-seeded Czech left-hander Lucie Safarova 6-4, 7-5 and the fifth-seeded former No. 1 Sharapova handled fellow Russian Anastasia Pavlyuchenkova 6-4, 7-6 (7-2). Halep and Sharapova will square off Friday in a rematch of the French Open final, which was won by the tall Russian.

Sharapova titled here in 2011 and was the Cincinnati runner-up in 2010.

An upset came when Ukrainian Elina Svitolina took out 15th-seeded Spaniard Carla Suarez Navarro 4-6, 6-4, 6-4. Svitolina will face ninth-seeded Ana Ivanovic, who battled past Svetlana Kuznetsova 6-2, 2-6, 6-3.

Agnieszka Radwanska. who was last week's titlist in Montreal, eased past Sabine Lisicki 6-1, 6-1, while Dane Caroline Wozniacki defeated 2012 Cincinnati runner-up Angelique Kerber 7-5, 6-2.