Lorenzi, Isner advance

Houston - Seventh-seeded Paolo Lorenzi overpowered Austrian qualifier Gerald Melzer 6-2, 6-2 in the opening round of the ATP Tour's US Clay Court Championships on Tuesday.

The 31-year-old Italian Lorenzi, who won the doubles title at Vina del Mar earlier this year, blasted three aces, had two double faults and won 68 percent of his first-serve points.

It was the first career match between world No 62 Lorenzi and the 22-year-old Melzer, who is the younger brother of Austrian star Jurgen Melzer. Jurgen was runner-up at Houston in 2006.

Lorenzi next faces countryman Flavio Cipolla, who beat Argentine qualifier Facundo Arguello 4-6, 6-4, 7-5.

In the night match, returning finalist John Isner engineered a 7-6 (7/4), 6-4 win over Ryan Harrison. Isner finished runner-up to Argentine Juan Monaco last year in Houston.

In other matches on Tuesday, American Robby Ginepri notched his first tour-level win in more than a year as he rolled over eighth seed Michael Russell 6-2, 6-2.

In another all-American first round match, wild card Jack Sock converted his two break points chances to beat qualifier Bradley Klahn 7-6 (7/3), 6-3.

Results from the second day of the US Clay Court Championships on Tuesday:

1st rd

Paolo Lorenzi (ITA x7) bt Gerald Melzer (AUT) 6-2, 6-2

Robby Ginepri (USA) bt Michael Russell (USA x8) 6-2, 6-2

Flavio Cipolla (ITA) bt Facundo Arguello (ARG) 4-6, 6-4, 7-5

Jack Sock (USA) bt Bradley Klahn (USA) 7-6 (7/3), 6-3

Ricardas Berankis (LTU) bt Jesse Levine (CAN) 6-7 (3/7), 7-5, 6-4

Fernando Verdasco (ESP x6) bt Steve Johnson (USA) 7-6 (7/5), 6-2

John Isner (USA x5) bt Ryan Harrison (USA) 7-6 (7/4), 6-4