The Little Sister couldn't have played bigger, on a grander occasion. For nearly two sets, Serena Williams had owned all the power, all the energy, in the U.
S. Open final. Martina Hingis was a beaten woman. The only question left was whether Williams could conquer her own nerves. She didn't manage that, up 5-3, 15-40, in the ninth game of the second set. Williams hadtwo match points, and frittered them both away. Her backhand, usually the most dependable shot of all, started floating over the baseline. Hingis just put the ball in the court, and watched as her 17-year-old opponent unraveled. Hingis, smart as ever, was playing defense. "I was very upset with myself," Williams said. "Something went dreadfully wrong. There comes a time when you have to stop caving.
" Williams gathered herself together again, coming back from 12 unforced errors in three games. She reached a second-set tiebreaker. When Hingis made the mistake of pressing the action, Williams had less time to think. Less was better. She instinctively hit the lines. Finally, tied at 4-4 in the tiebreaker, Hingis was the one to crack. She dinked in a second serve that Williams nailed for a winning forehand return. She struck a long backhand lob. When Hingis' backhand carried long, it was over, 6-3, 7-6 (7-4). "Oh my God," Williams said, walking in a happy fog behind the baseline. She won the U.
S. Open yesterday, the first African-American woman since Althea Gibson to hold the trophy, with a show of force that knocked over Hingis and promised more of the same for years to come. There was real joy in this victory. Everybody seemed to come out to watch the last, dramatic moments inside Arthur Ashe Stadium, because there was something about the Williamses that brought democracy to the place. All the food workers, all the ticket-takers, materialized from nowhere to agonize, then to cheer. Afterward, the President and Chelsea called from New Zealand. Richard Williams, the architect of this moment, climbed down from the stands to hug his daughter and tell her she had done it. He had been wandering in and out of his seat down the stretch, a mess of nerves. Smiling now, he took some snapshots with a small camera, from much too far away, that may show a dot of a teenager holding a speck of a silver trophy. "I was always the one who said she wanted to win the U.
S. Open and Venus was always the one who said she wanted Wimbledon," Serena said. "Opportunities don't come too often. If you don't take them, they may not come again.
" Serena made the most of this chance, aided by Hingis' three-set death struggle against sister Venus the night before. Hingis, usually an aggressive shotmaker, finished the match with no aces and only seven winners. Williams fired eight aces and 36 winners. Richard Williams said afterward that Hingis played "scared" out there, for much of the match. "Tired," probably would have been more accurate. "I wasn't the only person at the end who was scared," Hingis said. "I wasn't scared. If anybody, it was her at the end. I'd been there before in a big match. "I had a hard time falling asleep last night," Hingis said, about the hours after her Venus escape on Friday. "Serena was always leading. I felt like I was always behind, a step late. There were so many errors today.
" At the end of the 1999 Grand Slam season, Serena climbed to No. 4 in the women's rankings, her highest ever. Venus is No. 3, behind Lindsay Davenport at No. 2, while Hingis is No. 1. It didn't look that way yesterday. Then again, Serena is just 17, Hingis is 18, Venus is 19. Anna Kournikova, who missed this tournament but can join the group if she conquers her own service problems, is 18. "There are many years to go, against the Williamses," Hingis said. Yesterday, Serena Williams grabbed a first Slam for the Williams family. Anything goes, from here.