Top seeded American Andy Roddick blasted 22 aces on his way to a 7-6, 7-6 victory over compatriot Robby Ginepri in the quarter-finals of the Kroger St Jude ATP event in Memphis on Friday.

The world number three will face Kenneth Carlsen in the semi-finals after the unseeded Dane edged American Jan-Michael Gambill 7-6, 7-5.

Second seed Tommy Haas had an easier time than Roddick as the German eased to a 6-4, 6-3 victory over fifth-seeded Xavier Malisse of Belgium without facing a break point.

Hass will next play eighth seed Max Mirnyi after the Belarussian outlasted France's Antony Dupuis 7-6, 7-6.

In the WTA event, defending champion Vera Zvonareva defeated fellow Russian Evgenia Linetskaya 6-4, 6-1.

The top-seeded Zvonareva will play third-seeded American Meghann Shaughnessy for the women's title on Saturday.

Shaughnessy edged a 7-6, 7-6 thriller over 15-year-old Czech prospect Nicole Vaidisova who staved off five match points in the second set before succumbing on the sixth.