Top seed Andy Roddick [Images] defeated unseeded Frenchman Arnaud Clement 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 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 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 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.

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