Top seed Andy Roddick [ Images ] defeated unseeded Frenchman Arnaud Clement [ Images ] for the first time on Wednesday to advance to the quarter-finals of the Kroger St Jude championships in Memphis, Tennessee.

Seeking a second consecutive ATP title after taking the San Jose Open last weekend, the American world number three won 6-3, 6-3 in the second-round match, claiming a maiden victory over Clement after two previous defeats.

Roddick's victory sets up a last eight encounter against the winner of Thursday's match between compatriots Mardy Fish [ Images ] and Robby Ginepri.

Third seeded Tommy Haas [ Images ] of Germany [ Images ] maintained his good form and broke serve three times en route to a 6-4, 6-4 first-round victory over American qualifier Jeff Salzenstein.

Haas reached the semi-finals in San Jose before losing in straight sets to Roddick.

In the WTA event, top seed and defending champion Vera Zvonareva [ Images ] of Russia [ Images ] beat France's [ Images ] Severine Beltrame 7-6, 6-3 and third-seeded American Meghann Shaughnessy defeated Hana Sromova of the Czech Republic 6-3, 6-2 in second-round matches.

Promising seventh seed Nicole Vaidisova [ Images ] looked strong in her 6-2, 6-2 second-round win over Puerto Rican Kristina Brandi.

In the quarter-finals, the 15-year-old Czech will play unseeded American Jamea Jackson, who upset second seeded Amy Frazier in the first round and Bulgaria's Sesil Karatantcheva on Tuesday.