MEMPHIS (AFP) - Andy Roddick took another step toward a first title of 2009, easing into the quarter-finals of the 1.22 million-dollar ATP and WTA hardcourt tournament here Thursday. The top-seeded American needed just 61 minutes to dispatch compatriot Robby Ginepri 6-2, 6-3. Roddick, ranked sixth in the world, improved to 9-1 against Ginepri in his career. Roddick fired 11 aces and won 77 percent of his first-serve points. He converted four of his 12 break point chances. The 26-year-old Roddick, who won this event in 2002 and reached the finals on two other occasions, will face big-serving compatriot Sam Querrey, the eighth-seed, who steamrolled Marcos Baghdatis of Cyprus 6-1, 6-2. American seventh seed Mardy Fish was the only seeded man to fall Thursday, suffering a 6-2, 6-4 setback to Christophe Rochus of Belgium. Second seed Juan Martin Del Potro of Argentina and fifth-seeded Czech Radek Stepanek booked a quater-final clash. Del Potro defeated Latvian Ernests Gulbis, 6-3, 6-4, while Stepanek defeated Austrian Stefan Koubek 6-2, 6-4. Former world number one Lleyton Hewitt of Australia downed Davis Cup teammate Chris Guccione 6-2, 7-6 (7/4) to line up a meeting with Rochus. Russian Igor Kunitsyn and Dudi Sela of Israel were the other unseeded players to advance. In women's action, top-seeded Caroline Wozniacki had to battle past Dutch qualifier Michaella Krajicek to book her semi-final berth. The Dane needed two hours nine minutes to subdue Krajicek 2-6, 6-3, 6-3 and advance to a semi-final meeting with fourth-seeded Briton Anne Keothavong. And she got some help from Krajicek herself, who coughed up six double-faults in the third set. Wozniacki, 18, reached her first WTA semi-final of the season. She enjoyed a breakout year in 2008, winning the first three titles of her career and rising to a career-best ranking of 12th. Keothavong advanced with a 6-2, 1-6, 6-2 victory over fifth-seeded Marina Erakovic of New Zealand. Sixth-seeded German Sabine Lisicki continued the push toward her first title with a 6-3, 6-4 win over third-seeded Czech Lucie Safarova. In the semi-finals Lisicki will face second-seeded Belarussian Victoria Azaranka, who downed eighth-seeded Pauline Parmentier of France 6-4, 6-2.