Venus Williams defeats Kvitova in Miami

Venus Williams, playing in her first tournament since the U.S. Open due to Sjogren's syndrome, posted a second- round win over reigning Wimbledon champion Petra Kvitova Friday at the Sony Ericsson Open.

Williams defeated the third-seeded Kvitova 6-4, 4-6, 6-0 on the hardcourts at the Tennis Center at Crandon. The American Williams titled here in 1998, 1999 and 2001.

World No. 1 star Victoria Azarenka also posted a second-round win Friday.

After enjoying an opening-round bye, the Australian Open champion Azarenka took to the courts on Day 4 to handle Dutchwoman Michaella Krajicek 6-3, 7-5 in 1 hour, 42 minutes.

The 22-year-old Azarenka is the reigning Miami champ, having beaten Maria Sharapova in last year's finals here. The Belarusian also topped Sharapova in last week's lucrative finale at Indian Wells.

Azarenka, who's now 24-0 this season, also titled in Miami in 2009 and will face Britain's Heather Watson on Sunday. Her outstanding start is the best on the WTA since Martina Hingis went 37-0 to open her 1997 campaign.

Ninth-seeded Vera Zvonareva was stunned by little-known Spanish wild card Garbine Muguruza Blanco, 6-4, 6-4. The 18-year-old Muguruza Blanco is making her WTA debut this week and is 2-0 thus far.

The two-time major finalist Zvonareva is now a pedestrian 5-5 this season.

Fifth-seeded Pole Agnieszka Radwanska continued her recent winning ways with a 6-1, 6-1 pasting of American qualifier Madison Keys. Radwanska titled in Dubai last month.

Fifteenth-seeded former world No. 1 Ana Ivanovic moved on with a 6-4, 7-5 victory over American Vania King. The former French Open titlist from Serbia was a semifinalist at Indian Wells last weekend.

Playing in only her second match since returning from cancer treatment, wild card Alisa Kleybanova succumbed to fellow Russian Maria Kirilenko 7-6 (7-1), 6-3 on Friday.

In other action involving seeds, No. 7 Marion Bartoli of France defeated Polona Hercog 5-7, 6-2, 6-1; Russian Ksenia Pervak edged No. 11 Italian Francesca Schiavone 6-4, 4-6, 7-5; No. 16 Slovak Dominika Cibulkova handled Georgian Anna Tatishvili 7-5, 6-1; No. 18 Chinese Zheng Jie got past German Angelique Kerber 7-6 (7-4), 6-1; No. 20 Slovak Daniela Hantuchova downed Ukrainian Kateryna Bondarenko 6-7, 6-2, 7-6; No. 24 Italian Flavia Pennetta outlasted Spaniard Lourdes Dominguez Lino 6-4, 2-6, 6-0; the wild card Watson drove out No. 27 Czech Lucie Safarova 6-2, 6-1; Canadian Aleksandra Wozniak ousted No. 28 Romanian Monica Niculescu 4-6, 6-3, 6-4; Spaniard Silvia Soler Espinosa toppled No. 31 Estonian Kaia Kanepi 7-5, 6-3; and Romanian Simona Halep humbled No. 32 Russian Nadia Petrova 6-3, 6-2.

The winner of the $4.828 million tournament will collect $712,000.