New York - Predictions of rain came true with the worst possible timing to leave Rafael Nadal hanging in his US Open quarter-final against Fernando Gonzalez with a 7-6 (7-4), 6-6 (3-2) lead early Friday morning. Two rain interruptions during the last of the men's quarter-finals mean the Spaniard and his Chilean opponent must finish later in the day - weather permitting - in order for the event to return to schedule.
A year ago the men's final at the Grand Slam was played on a Monday after similar bad luck. Friday's forecast predicts more rain from an Atlantic storm sweeping into the New York area.
In addition to the held-over Nadal-Gonzalez match, the women's semi-finals are due to be played, with Serena Williams facing Kim Clijsters, and teenagers Caroline Wozniacki and Yanina Wickmayer playing for the first time at this stage.
Earlier, Argentinian Juan Del Potro won a battle of 20-year-olds with a 4-6, 6-3, 6-2, 6-1 comeback Thursday over Croatian Marin Cilic to make his biggest career impression at a Grand Slam.
Roger Federer and Novak Djokovic moved through safely on Wednesday and have two days off before Saturday's scheduled semis.
The Open is the only major which does not allow competitors a day off between matches, squeezing in men's semis and the women's final on the concluding "super Saturday" before the men play their best-of-five-set final on the Sunday.
The television-driven schedule has been under fire for years, with this year and last particularly troublesome.
Nadal and Gonzalez were forced off court for 76 minutes at 2-2 in the second set, then came back and played for just over half an hour before more showers moved in.
More delays produced the post-midnight announcement which sent a disappointed public and frustrated players home.
Sixth-seeded Del Potro shrugged off an opening set against Cilic that he would likely prefer to forget before he turned the tide in the second set and strode to victory.
Del Potro, born within a few days of his opponent, lost only three of the last 20 games as he imposed his will on the Croatian, whose own big game deserted him after he had won the first set and going up a break in the second.
"I don't know how I turned it around," said Del Potro, holder of six career titles. "I fought to the end. This was a beautiful win."
Gusty conditions were "tough for both players," he said.
"I was so focused on my serve," Del Potro said. "I didn't miss many easy balls, and Marin was playing very well. In an important match like this, you feel nervous. I was thinking on every point, just trying to keep the ball inside the court."
The victory will lift the number six Del Potro back into the top five in Monday's rankings and makes him the third Argentinian to reach the New York semis after Guillermo Vilas (1975-77, 1982) and David Nalbandian (2003).
Del Potro could do no wrong after making his move on Cilic, with the Argentinian at one point breaking the Croatian's serve on four straight occasions in the second and third sets.
Del Potro is playing the event for the second time, compiling an 11-3 record.
He stands 2-4 against Nadal but has won their last two meetings while trailing Gonzalez 1-3, but defeated the Chilean in their last match this summer in Washington.
