Top-ranked Andre Agassi and French Open champion Juan Carlos Ferrero advanced to a US Open semi-final showdown here Friday while Andy Roddick won his 17th match in a row to set a date with David Nalbandian.

Eight-time Grand Slam champion Agassi beat Argentine fifth-seeded Guillermo Coria 6-4, 6-3, 7-5 and Spanish third seed Ferrero won eight of the last nine games to oust Australian sixth seed Lleyton Hewitt 4-6, 6-3, 7-6 (7/5), 6-1.

US fourth seed Roddick fired 15 aces to down Dutch 12th seed Sjeng Schalken 6-4, 6-2, 6-3 while Argentina's 13th seed Nalbandian outduelled 21st-ranked Moroccan Younes El Aynaoui 7-6 (7/2), 6-2, 3-6, 7-5.

Agassi, who at 33 is the oldest man in the field and oldest to be ranked number one, could become the oldest US Open champion since 1970 when Australian Ken Rosewall won at age 35. Agassi advanced to his ninth US Open semi-final.

Ferrero agrees. He would overtake Agassi for the world number one ranking with a victory.

Ferrero is 2-1 against Agassi, winning a 2002 French Open quarterfinal and at last year's ATP Masters Cup while losing last year at Madrid. Roddick is 2-0 against Nalbandian, including a win in last month's Montreal final.

Roddick reached his third Slam semi-final of the year but first at the US Open, where he lost quarter-finals to eventual champions the past two years. A first Grand Slam title is within his reach, but he has work yet to grasp it.

Roddick's win streak is the ATP's longest of the year and includes titles at Indianapolis, Cincinnati and Montreal. Since pairing with former Agassi coach Brad Gilbert in early June, Roddick has lost only twice.

Blocking his path will be Nalbandian, the 2002 Wimbledon runner-up who beat Swiss second seed Roger Federer in the fourth round. Nalbandian is the first man from his land so deep here since Guillermo Vilas won the 1977 US Open.

Nalbandian, who took nearly three hours to win, and Ferrero will play their third matches in as many days, an unprecedented Slam test. Agassi and Roddick rested Thursday after sneaking in triumphs between raindrops earlier this week.

Reigning Australian Open champion Agassi won the US Open title in 1994 and 1999, but lost last year's final to Pete Sampras. Not since Mats Wilander in 1988 has an Australian Open champion won the US Open title in the same year.

Coria had a sore left hamstring and cut right thumb, aiding Agassi in making fast work of the South American to aid his chances against Ferrero in an event where rain wiped out rest days on the path to a Sunday final.

Coria battled through but could not conquer Agassi on key points.

Hewitt squandered two set points in the third set and when a left hip injury flared, he was unable to challenge Ferrero.

Roddick made a believer of Schalken with his powerful serve.