Sept. 11 (Bloomberg) -- Rafael Nadal’s U.S. Open quarterfinal against Fernando Gonzalez was postponed because of rain and will be completed later today, weather permitting.

Nadal, the men’s No. 3 seed, led 11th-seeded Gonzalez 7-6 (7-4), 6-6 when organizers halted play for the night after a second rain delay at the National Tennis Center in New York. Nadal was leading the second-set tiebreak 3-2.

The conclusion of the match, which was called off just after midnight local time, will be sandwiched between today’s women’s semifinals and resume no earlier than 5 p.m., with the start dependent on the weather and court availability, the U.S. Tennis Association said. The winner advances to play Argentina’s Juan Martin Del Potro in the semifinals.

Defending champion Serena Williams will play Belgium’s Kim Clijsters in the first women’s semi and Caroline Wozniacki of Denmark later faces unseeded Yanina Wickmayer of Belgium. There’s a 90 percent chance of rain today in Flushing Meadows, according to the National Weather Service.

Yesterday’s two rain delays lasted more than 2 1/2 hours and were the first weather interruptions at this year’s U.S. Open. Twelve months ago, heavy rains from Tropical Storm Hanna interrupted Nadal’s semifinal loss to Andy Murray, pushing it to a Sunday finish. It postponed the women’s singles final to Sunday and resulted in the first Monday men’s final since 1987.

Nadal won the first four points in the opening set tiebreaker last night against Chile’s Gonzalez and then sought assistance from the trainer for an apparent abdominal injury.

The Spaniard had an abdominal problem attended to during his third-round win against Nicolas Almagro and has declined to talk about the injury.

Slippery Lines

Four games into the second set, the match was delayed for more than an hour because of rain. It was stopped again for more than 90 minutes after the rain returned and the court’s painted lines got too slippery during the second-set tiebreaker.

Nadal, a six-time Grand Slam winner, is seeking to reach the U.S. Open semifinals for the second straight year. This is the only major title he hasn’t won.

The sixth-seeded Del Potro lost the first set yesterday against Croatia’s Marin Cilic and was a service break down in the second before rallying for a 4-6, 6-3, 6-2, 6-1 win.

Del Potro also made the semifinals of the French Open this year, losing to eventual winner Roger Federer. He becomes the third Argentine to reach the last four at the season’s final Grand Slam after Guillermo Vilas and David Nalbandian.

Five-time defending champion Federer and fourth-seeded Novak Djokovic will meet in the other semifinal.

To contact the reporter on this story: Erik Matuszewski at the U.S. Open in New York at matuszewski@bloomberg.net

Last Updated: September 11, 2009 00:57 EDT