Flushing Meadows, NY (My Sportsbook) - Two-time champion Venus Williams and another former champ, Kim Clijsters, were a pair of second-round winners Wednesday at the U.S. Open, the final Grand Slam event of the year.

A third-seeded Venus, slowed a bit by a sore knee, handled fellow American Bethanie Mattek-Sands 6-4, 6-2 at the Billie Jean King USTA National Tennis Center. Venus closed Mattek-Sands out with an unreturnable serve on Day 3.

The former top-ranked Venus titled here back-to-back in 2000 and 2001 and was the Big Apple runner-up in 1997 and 2002. The big American owns seven major titles and was this year's Wimbledon runner-up to her younger sister Serena.

Up next for Venus will be Slovakian Magdalena Rybarikova, a 4-6, 6-2, 6-2 winner against Taipei's Kai-Chen Chang.

An unseeded Clijsters started slow before charging back to oust 14th-seeded Frenchwoman Marion Bartoli 5-7, 6-1, 6-2. The Belgian star closed out the 2007 Wimbledon runner-up Bartoli with an emphatic ace.

The former world No. 1 Clijsters returned to the WTA Tour just last month after retiring from it in the spring of 2007. She captured her lone Grand Slam title here in New York back in 2005, which was the last time she performed in Flushing until this season. Clijsters was also the runner-up here in 2003.

Clijsters' third-round opponent will be fellow Belgian Kirsten Flipkens.

Seventh-seeded Vera Zvonareva came from behind to best fellow Russian Anna Chakvetadze 3-6, 6-1, 6-1, while eighth-seeded Belarusian Victoria Azarenka whipped Czech Barbora Zahlavova Strycova 6-2, 6-1, and 10th-seeded Italian star Flavia Pennetta advanced with a 6-0, 6-0 double-bagel spanking of helpless Indian Sania Mirza. The capable Azarenka was a big winner at the "Fifth Slam" in Miami earlier this season, while the rising Pennetta titled on a hardcourt in Los Angeles last month.

Russian glamour girl Maria Kirilenko pulled off an upset by dousing 12th- seeded Pole Agnieszka Radwanska 6-4, 2-6, 6-4, while fading former world No. 1 Amelie Mauresmo was an upset victim, as the 17th-seeded Frenchwoman succumbed to Canadian Aleksandra Wozniak 6-4, 6-0. Mauresmo piled up 31 unforced errors and struck a mere nine winners en route to defeat.

The 30-year-old Mauresmo is a two-time major titlist who has been a non-factor on the tour the last couple of seasons. This marked her earliest-ever exit in 10 trips to Flushing.

In other action involving seeds, No. 18 Chinese Li Na leveled Portuguese teenager Michelle Larcher de Brito 6-1, 6-3; the aforementioned Flipkens upended No. 20 Spaniard Anabel Medina Garrigues 6-1, 6-3; No. 26 Italian Francesca Schiavone drilled Swiss Stefanie Voegele 6-4, 6-4; and No. 31 Russian Elena Vesnina handled American veteran Jill Craybas 7-6 (8-6), 6-1. Vesnina was last week's New Haven runner-up to Top-10 Dane Caroline Wozniacki.

Another second-round victor was Spaniard Maria Jose Martinez Sanchez, who erased German Angelique Kerber 7-5, 6-3.

The second round is scheduled to conclude here on Thursday, including matches for current world No. 1 Dinara Safina, fourth-seeded Elena Dementieva, 2008 U.S. Open runner-up Jelena Jankovic and former U.S. Open champion Maria Sharapova.

The French Open and Australian Open runner-up Safina will face German Kristina Barrois, while the reigning Olympic gold medalist and 2004 U.S. Open runner-up Dementieva will battle American Melanie Oudin, the fifth-seeded Jankovic will encounter Kazakhstan's Yaroslava Shvedova, and a 29th-seeded Sharapova, who titled here in 2006, will take on American Christina McHale.

Also on Thursday's schedule will be sixth-seeded Svetlana Kuznetsova and a ninth-seeded Wozniacki. The French Open champion and former U.S. Open titlist Kuznetsova will tangle with Latvian Anastasija Sevastova, while last week's Pilot Pen winner Wozniacki will be opposed by Croat Petra Martic.