MEMPHIS, Tennessee (AFP) - Top-seeded American Andy Roddick made a quick start at the ATP/WTA tennis tournament here Wednesday with a straight-set first-round victory over qualifier Gilles Muller.

Roddick, seeking as second title in as many weeks after his triumph at San Jose, California, on Sunday, defeated Luxembourg's Muller 6-4, 7-6 (7/4) to book a clash with fellow American Mardy Fish.

Roddick, who won the Memphis title in 2002, captured his 24th ATP title at San Jose on Sunday, downing Czech Radek Stepanek in the final.

With Wednesday's win, the 25-year-old Roddick remains undefeated in the opening round in his last eight trips here and improved to 22-6 in Memphis, where he has made the quarter-final round in every year except in his 2001 debut.

In one of three second-round men's matches, third-seeded seed Tommy Haas fell to fellow German Benjamin Becker 3-6, 6-2, 7-5.

Haas, a two-time defending champion, was making his 10th appearance in this event where he beat Jim Courier in the 1999 final. The loss snapped his 11-match win streak here.

In other second-round action, the fourth-seeded Stepanek advanced with a 7-6 (8/6), 2-6, 7-5 win over France's Florent Serra. Seventh seed Jurgen Melzer of Austria was not as fortunate, losing to Steve Darcis of Belgium 6-3, 7-6 (7/4).

Sweden's Robin Soderling, the eighth seed, beat Canadian qualifier Frederic Niemeyer 6-2, 6-1 in the only remaining first-round match.

In women's action, fourth-seeded American Lindsay Davenport breezed past Russia's Evgeniya Rodina of Russia 6-1, 6-1.

Davenport, 31, has enjoyed a triumphant return to the WTA Tour following the birth of her first child last summer.

In six tournaments since returning in September, Davenport has gone 21-2 and claimed titles at Bali, Quebec City and Auckland.

A former world No. 1 and owner of 54 career titles, Davenport is the highest remaining seed in the top of the draw following the ouster of top seed Venus Williams, who was stunned by Czech qualifier Petra Kvitova on Tuesday.

Kvitova herself fell Wednesday to Russian Alla Kudryavtseva 6-7 (6/8), 7-5, 6-1

Third seed Shahar Peer of Israel, who lost to Williams in the championship match last season, is back in the quarter-finals after beating Hungarian Melinda Czink 6-0, 3-6, 6-2.

Sixth-seeded Caroline Wozniacki of Denmark will play Davenport in the quarter-finals after defeating Portugal's Michelle Larcherde Brito 6-2, 6-4.