NEW YORK - The swirling winds in Arthur Ashe Stadium caused as much trouble for Juan Martin del Potro as his opponent, Marin Cilic.
Del Potro overcame them both Thursday and moved into his second Grand Slam semifinal.
The sixth-seeded Argentine overcame a sluggish first set and figured out the blustery wind inside the cavernous stadium to defeat No. 16 Marin Cilic, 4-6,6-3, 6-2, 6-1 in the U.S. Open quarterfinals.
"I cannot start the match like today," Del Potro said. "I was thinking about other things, and the weather was bad. But it was bad for both players. I just need to be in focus in the beginning of the match until the last point and play my game."
Later, the wind turned into rain and delayed No. 3 Rafael Nadal's match against No. 11 Fernando Gonzalez twice, the second time with Nadal up one set and the second tied at 6.
They may have been welcome breaks for Nadal, who needed a medical timeout in the first set to have work done on his stomach, an injury that's been bothering him throughout the tournament.
The winner plays del Potro, who was having a rough time handling Cilic's serve in the first set and was down a break early in the second. That's when he figured things out and rolled off 17 of the last 20 games.
"He was not missing," Cilic said.
Del Potro is in his second major semifinal, adding this to his trip at the French Open this year, where he blew a lead and lost in five sets to Roger Federer.
Del Potro got a matchup with Cilic thanks to the Croatian's three-set upset over No. 2 Andy Murray on Tuesday. In del Potro, Cilic saw a near mirror image of himself: 6 feet 6, big serve, and they were even born five days apart in September 1988.
But Cilic's sharpness from the Murray match vanished in this one. He committed 53 unforced errors against 29 winners, and del Potro was on his game. He had 24 unforced errors and 27 winners.
"Andy, he doesn't have as much power as del Potro has," Cilic said. "And it was a little bit hotter that day, and the ball was going through the court more and jumping much more."
This match was played with temperatures in the mid 60s and winds that gusted at around 20 mph at times.
WILLIAMSES IN DOUBLES FINAL: Venus and Serena Williams advanced to their 10th Grand Slam doubles final with a 7-6 (7-4), 3-6, 6-2 victory over Alisa Kleybanova and Ekaterina Makarova.
The sisters are 9-0 in their previous final appearances, though this is their first trip to the U.S. Open final since 1999.
"Hopefully, that's a record that won't end yet," Serena said. "We really want this. I'm sure whoever we play really wants it, too."
The other semifinal was scheduled for Friday.
A 10th Grand Slam title would put the Williamses halfway to the record shared by Pam Shriver and Martina Navratilova.
FIRST TIME A CHARM: Travis Parrott and Carly Gullickson put a new spin on how to succeed without really trying, winning the mixed doubles title in their first tournament together, a pairing that flourished more out of desperation than preparation.
They formed their winning combination two days before the tournament began, then received a wild-card entry even though they'd missed the deadline.
"I was superrelaxed because I felt no pressure on the court, because it was just fun," said Gullickson, daughter of former major-league pitcher Bill Gullickson, after a 6-2, 6-4 victory over defending champions Cara Black and Leander Paes.
Parrott's original partner, Abigail Spears, decided to play with Robert Kendrick because Kendrick had a wild-card spot secured. Gullickson and her original partner, Rajeev Ram, weren't ranked high enough to get a spot in the draw.
After Parrott got dropped by Spears, he heard Gullickson was looking for a teammate. He sent a text. And that's how a champion was born.
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Women's semifinals: Serena Williams (2) vs. Kim Clijsters; Caroline Wozniacki (9) vs. Yanina Wickmayer
TV: 12:30 p.m., Ch. 10