WINSTON-SALEM, N.C. — Andy Roddick advanced to the quarterfinals of the Winston-Salem Open on Wednesday night,by beating Santiago Giraldo 6-1, 6-3.

WINSTON-SALEM, N.C. — Andy Roddick advanced to the quarterfinals of the Winston-Salem Open on Wednesday night,by beating Santiago Giraldo 6-1, 6-3.

Playing in the final men's tuneup before the U.S. Open, Roddick showed sharp form for the second match in a row.

In the process, he showed signs that he might be recovered from summer ailments in time for the final Grand Slam event of the year. This was just his third match in the last six weeks because of an abdominal strain.

Giraldo led the second set 2-1 before Roddick took the next three games to regain control.

Until this week, Roddick hadn't won a match since the second round of Wimbledon, recovering from an abdominal injury during much of that time. Now he has won on back-to-back nights.

Roddick will face Juan Monaco today. Monaco, from Argentina, beat Kei Nishikori 6-0, 6-3.

John Isner, the No. 4 seed, beat 13th-seeded Jarkko Nieminen 7-6 (4), 6-2.

Isner, a native of nearby Greensboro, solved Nieminen's serve and needed just 23 minutes to win the second set.

In the quarterfinals, Isner will face Marcos Baghdatis, who beat Steve Darcis 7-5, 6-0. Isner lost only seven points out of 51 on his serve. The match ended, appropriately, with an ace.

New Haven Open

At New Haven, Conn., Li Na of China had to battle from behind in each to beat Russia's Maria Kirilenko 6-4, 7-6 (4) in the second round of the New Haven Open, the final WTA tournament before the U.S. Open.

The French Open champion had trailed 3-1 in the first set and 4-1 in the second, before securing the straight-set win and a berth in the quarterfinals.

Li will next face another Russian, Anastasia Pavlyuchenkova. The eighth seed also won in straight sets, beating Roberta Vinci of Italy, 6-2, 6-4 after jumping out to a 5-1 lead early.

Spaniard Anabel Medina Garrigues also moved into the quarterfinals, overcoming a knee injury to beat Elena Vesnina of Russia 6-2, 7-6 (5).

Marion Bartoli of France also advanced to the quarterfinals with a 6-2, 2-6, 6-1 win over Klara Zakopalova of the Czech Republic.

The fourth-seeded Bartoli broke Zakopalova's serve three times in the first set, but was broken three times in the second. She regained her form, cruising in the final set.