Say one thing for rain at the U.S. Open, it does wonders for those fans lucky enough to arrive after it stops.

The grounds of what is now known as the USTA Billie Jean King National Tennis Center were jam packed yesterday with fans and food and, after a dreary day of delays, tennis. More tennis than anyone could hope to digest in an afternoon. The USTA scheduled 80 matches in singles and doubles, shuttling fresh men and women on court as soon as the weary ones said their goodbyes.

Top-ranked players accustomed to the cavernous Arthur Ashe Stadium, or the cozy confines of Louis Armstrong, were strewn about the grounds and made to grapple with chatting fans, cell phones, and music. There was David Nalbandian, the no. 3 seed, extricating himself from another two-set deficit on Court 11. Tomas Berdych, an up-andcomer seeded no. 13, toying with Boris Pashanski on Court 13. Dmitry Tursunov, the Russian who is just as much a Californian, trundled his bags to Court 6. Thomas Johansson, a former Australian Open champion, and Sebastien Grosjean played a quarterfinal-quality five-setter on Court 10. Even James Blake, the top-ranked American, had his permit for Ashe revoked, in favor of Roger Federer and Rafael Nadal.

Nadal opened the afternoon with a 6–4, 6–4, 6–4 victory over Mark Philippoussis, the 6-foot 5-inch, hard-serving Australian whose best days are behind him. The 20-year-old Spaniard’s steady topspin forehand carried the day. More impressive, however, was his instinct for attacking the net and volleying, a skill he is developing with alarming speed. Nadal has an excellent draw, and seems ready, after a sleepy summer, to make a deep run at the Open, so long as he recovers from the upset stomach that troubled him after the match.

“I play very aggressive today, more than the last weeks,” Nadal said. “I like this city, and I want to play good here. That’s one of my special goals of the year.”

Federer was good, too, but that’s expected of the two-time defending champion. He made quick work of Yeu-Tzuoo Wang, a 21-year-old from Taipei who made his U.S. Open debut, 6–4, 6–1, 6–0. The world no. 1 won 36 of 40 points on his first serve and next faces British veteran Tim Henman, whom he has defeated easily in their last four meetings.

“I thought I played pretty well,” Federer said. “Not too many mistakes.”

Serena Williams was every bit as dominant in defeating Lourdes Dominguez Lino, 6–1, 6–2. The former world no.1 needed a wild card into this year’s draw, after missing much of the year because of injuries and her at times flagging commitment to tennis. Yesterday she said she had no doubts that she could again become the no. 1 player in the world. The question at the Open is, is she in shape enough to win?

Williams’s post-match press conferences are erratic affairs, usually populated by more questions about her fashion sense (this year’s influence is Asian) and modest acting career than her tennis. When the subject of her fitness did come up, Williams artfully bobbed and weaved — “Everyone has their ups and downs” — before at least saying she felt far better than last year, when she lost to her sister Venus in the fourth round.

“When that first set went an hour, I knew my U.S. Open was done,” Williams said.”This year is a totally different story. I’m at six hours.”

Prior to the Open, Williams, accompanied by her father Richard, spent a week training with Nick Bollettieri in Florida. There’s no doubt that her once fearsome strokes have improved since her return to the tour earlier this summer — one only needed to witness Lino endure 34 Williams winners. What will happen when she comes up against a woman who hits as hard as she does, such as Ana Ivanovic, who struggled but won yesterday, or the top seed, Amelie Mauresmo, is anyone’s guess. Williams next faces Daniela Hantuchova, who defeated her at the Australian Open earlier this year.

While Williams looks to recapture her past, James Blake seems to remain on the border of letting a fine present — the no. 5 ranking in the world and three titles this year — slip away.

Blake played impatiently and erratically most of the summer, and he nearly found a way to lose control of his match with Juan Monaco yesterday, before prevailing 6–2, 7–5, 7–6(7). It was a contest of uncomfortable swings. The 26-year-old American took a 3–1 lead in the second set, and then poof, he trailed 5–3. Monaco came to his aid with some terrible play. Blake led 5–2 in the third set. He also trailed 6–5. He led 6–3 in the final tiebreaker, but squandered those three match points, and another, before he held. He also seemed to cramp as the set neared its conclusion.

Despite his impressive run to the quarterfinals last year, when he lost to Andre Agassi in five sets, and his excellent results since, Blake seems uncertain that he belongs inside the top five. It’s a wonder why: He moves as well as anyone on the tour, and his forehand rivals Federer’s in pace and penetration, if not consistency. At times yesterday, Blake seemed to lose his identity. His feet became heavy, and he slapped at the ball and tried to redirect it early in rallies, rather than waiting for a better opportunity.

“I had some pretty bad little runs there, some hiccups, whatever you want to call them,” Blake said, adding that he did not like to enter tournaments with grandiose expectations. “Just because Tennis magazine picked me to win this, I don’t worry about those kinds of things.”