-- The most formidable foe at the U.S. Open on Wednesday was the whipping wind.

It made Taylor Dent list like the Leaning Tower of Pisa when he unfurled his 6-foot-2, 195-pound frame to serve. And it made the impossibly lithe Maria Sharapova -- all 6-11/2 and 130 pounds of her -- grateful she'd eaten a piece of cake the previous day. Without the extra ballast, Sharapova quipped, she just might have been blown off court and into the stratosphere.

Gusting at more than 20 mph, the wind wreaked havoc on the finely tuned strokes of the world's best tennis players at the National Tennis Center, where the game's smartest practitioners throttled down the power on their serves, built in bigger margins of error on their groundstrokes and stayed perched on their toes so they could adjust lightning-quick to the freakish movement of the ball.

Those who adapted best were rewarded, and they included nearly all of the favorites, such as top-seeded Sharapova, who rolled over Dally Randriantefy of Madagascar, 6-1, 6-0, and into the third round.

"I was serving at 69 miles per hour," confessed Sharapova, who normally cracks serves at 110-plus mph. "It's pretty funny. It's even funnier from TV because they can't see the wind. These people probably think we look like beginners, that's the sad part!"

Also advancing were fourth-seeded Kim Clijsters, who easily subdued Fabiola Zuluaga of Colombia, 7-5, 6-0, and both Williams sisters, who moved one step closer to their scheduled fourth-round meeting.

Venus had the tougher task, assigned to Arthur Ashe Stadium for her second-round match at mid-afternoon, when the wind was at its wildest. Though she called it the windiest conditions she'd ever faced, the two-time U.S. Open champion hardly seemed rattled, defeating 18-year-old Maria Kirilenko of Russia, 6-1, 6-3.

"It was deathly windy!" Venus said. "It was just swirling at random." To compensate she slathered her strokes with spin so the ball would be more apt to stay in. And she shaved pace off her serves so they wouldn't sail long.

"I tried to not go for too much," she said, "but of course try to play the right shots, try to move forward and be more aggressive."

Serena took the grand stage during the evening session, after the wind had subsided and the stadium lights had come up -- all the better to flaunt her new diamond necklace and $40,000 diamond earrings, loaned by a Los Angeles jewelry designer in exchange for prime-time exposure on the ears of the sport's reigning diva. But in terms of both accessories and skills, Catalina Castano of Colombia was no match for the tournament's eighth seed, bowing out, 6-2, 6-2.

Serena announced to the crowd afterward that she would donate $100 for every ace she hits for the rest of the year to relief efforts on behalf of those who have lost so much in Hurricane Katrina.

"Last year we in Palm Beach got hit really bad," she explained later. "I can only imagine what it must be in New Orleans -- especially looking at all the footage, all the rain, all this horrible stuff. I thought it would be just a halfway decent gesture."

While women dominated the schedule on the blustery last day of August, a few of the game's top men were in action, as well.

Third-seeded Lleyton Hewitt had no trouble with a potentially tricky first-round opponent, Albert Costa of Spain, the 2002 French Open champion. Hewitt cruised, 6-1, 6-2, 6-1.

"Extremely tough conditions," said Hewitt, the 2001 U.S. Open champion and last year's runner-up. "It was one match you just wanted to get under your belt and get back into the locker room as quickly as possible."

But the skies opened and rain fell with a fury just as second-seeded Rafael Nadal of Spain and wild-card Scoville Jenkins of Atlanta strode onto court shortly before 9 p.m. for a highly anticipated battle of gifted 19-year-olds. Play was suspended for nearly 80 minutes, but Nadal had little trouble keeping his focus and advanced to the third round with a 6-4, 7-5, 6-4 victory.

Nadal's significance to the tournament looms even larger in the wake of Andy Roddick's shocking first-round ouster Tuesday night.

Former champion John McEnroe has hailed the charismatic Nadal as the most exciting player to come along in men's tennis in years, and the sport's marketing gurus are tripping over themselves to promote the young Spaniard, who brings a rare passion to the game -- along with his signature Capri pants and muscle shirts. Nadal is one of just three players to have beaten world No. 1 Roger Federer this year. On the opposite side of the draw, Nadal also represents the best chance of giving the supremely gifted Swiss a battle worth watching in the men's final, assuming Federer sails through as expected.

While Roddick's young career is a testament to Federer's mastery (Federer holds a 10-1 edge over the American), U.S. Open officials nonetheless based much of their marketing initiatives for the 2005 tournament on Roddick's quest to reclaim the title he won in 2003. So did American Express, which underwrites both Roddick's career and the tournament. But a streaky left-hander from Luxembourg, 68th-ranked Gilles Muller, sent Roddick packing in straight sets.

The stunning upset seemed to be on the minds of nearly every player left standing on Wednesday -- male or female, seeded or unseeded. "It can happen to anyone," Clijsters said. "It can happen to you, too."

Sporting $40,000 earrings, No. 8 Serena Williams easily advances and then offers to donate $100 for every ace she hits for the rest of the year to hurricane relief efforts.