Former world No. 1 superstar Serena Williams round victories, while the current ranked woman and defending champion Caroline Wozniacki was an upset victim at the $2.05 million Rogers Cup, a U.S. Open Series event.

The unseeded Williams won her seventh straight match with a 6-1, 7-6 (9-7) victory over capable German Julia Goerges in 1 hour, 37 minutes. Goerges was unable to break the American's lethal serve on Day 3.

Williams, who titled in Stanford last month to capture her first title of 2011, is now 11-2 since returning to WTA action back in June.

The 13-time Grand Slam champion Williams captured this Canadian event 10 years ago here in Toronto. She'll face China's Zheng Jie on Thursday.

Meanwhile, Italian Roberta Vinci, a three-time titlist on the WTA this season, ousted the Danish Wozniacki in 6-4, 7-5 fashion in 1 hour, 52 minutes Wednesday on the hardcourts at Rexall Centre. Wozniacki, who enjoyed an opening-round bye, dropped the second set despite leading by a pair of service breaks at one point.

Wozniacki, the owner of five titles this season, beat U.S. Open runner-up Vera Zvonareva in last year's Rogers Cup finale in Montreal, as this event shifts between Toronto and Montreal each year.

Third-seeded Russian Vera Zvonareva beat fellow countrywoman Nadia Petrova 7-5, 6-4, while fourth-seeded Victoria Azarenka demolished Canadian Stephanie Dubois 6-0, 6-0.

Sharapova, the No. 5 seed, took down Serbian Bojana Jovanovski 6-1, 7-5 to secure her spot in the third round.

French Open champion and Australian Open runner-up Li Na, seeded sixth this week, advanced via walkover, as fellow Chinese Peng Shuai was unable to go due to a hip injury; seventh-seeded Wimbledon titlist Petra Kvitova of the Czech Republic handled Spaniard Anabel Medina Garrigues 7-6 (7-3), 6-3; eighth-seeded French Open runner-up Francesca Schiavone of Italy leveled Russian Ekaterina Makarova 6-1, 6-3; and 10th-seeded Aussie Samantha Stosur erased Canadian wild card Aleksandra Wozniak 6-3, 6-4. Li and the former French Open runner-up Stosur will clash on Thursday.

Eleventh-seeded German Andrea Petkovic beat Hungarian qualifier Greta Arn 6-4, 7-5, while last week's Carlsbad champion Agnieszka Radwanska, seeded 13th this week, continued her winning ways with a 6-3, 6-3 victory over Croatian qualifier Petra Martic on Wednesday.

Former French Open champion Ana Ivanovic handled Czech Iveta Benesova 6-3, 6-2. Ivanovic captured this Canadian event in Montreal back in 2006.

In other second-round action, Czech Lucia Safarova subdued Ukrainian qualifier Simona Halep 6-2, 6-4, Russian qualifier Galina Voskoboeva doused Italian Flavia Pennetta 2-6, 6-3, 6-2, and Spanish qualifier Maria Jose Martinez Sanchez downed Slovakian Daniela Hantuchova 7-5, 6-2.

The 2011 Rogers Cup champion will earn $360,000.