Serena rolls into Rogers Cup quarters

Two-time champion Serena Williams was an easy third-round winner Thursday at the $2.369 million Rogers Cup tennis event.

The world No. 1 American superstar drubbed 13th-seeded Belgian Kirsten Flipkens 6-0, 6-3 on the hardcourts at Rexall Centre. Flipkens was a surprise Wimbledon semifinalist last month.

Williams captured this Canadian event in 2001 and 2011 and was the runner-up in 2000. The reigning U.S. and French Open champion's quarterfinal opponent on Friday will be hot Slovak Magdalena Rybarikova.

Agnieszka Radwanska, Li Na and reigning champion Petra Kvitova were also among Thursday's victors. The third-seeded Radwanska took out 14th-seeded American Sloane Stephens 6-1, 7-6 (7-2), while No. 6 seed Kvitova easily handled 12th- seeded Aussie Samantha Stosur in a 6-3, 6-3 verdict.

Stosur was the runner-up in Toronto two years ago and last week's surprise titlist in Carlsbad.

The fourth-seeded Li was taken to the limit by No. 16 seed and former world No. 1 Ana Ivanovic before prevailing by a 3-6, 6-1, 7-6 (7-5) score.

The former French Open champion and two-time Australian Open runner-up Li lost to Czech left-hander Kvitova in last year's Rogers Cup finale in Montreal, as this tournament shifts between Toronto and Montreal each year.

The Serbian Ivanovic, meanwhile, captured this event in Montreal in 2006.

The 2012 Wimbledon runner-up Radwanska will meet last year's French Open runner-up Sara Errani in the round of eight after the fifth-seeded Italian got past France's Alize Cornet 7-5, 7-6 (7-3).

An upset came when the surging Rybarikova vanquished seventh-seeded Wimbledon champion Marion Bartoli 7-6 (7-5), 1-0, as the French star retired after the first game of the second set due to an abdominal injury.

Rybarikova captured her second straight Washington, D.C., title last week.

Two more upsets occurred when Slovak Dominika Cibulkova knocked off 10th- seeded Italian Roberta Vinci 6-3, 7-6 (7-4) and capable Romanian Sorana Cirstea took out 15th- seeded Serb Jelena Jankovic 6-3, 6-4. The former world No. 1 Jankovic was the Toronto runner-up back in 2007.

Cibulkova will take on Li in Friday's quarters, with Cirstea next up for Kvitova.

The newest Rogers Cup titlist will claim $426,000.