From PEOPLE Magazine Click to enlarge
Records, they say, are made to be broken, and so it was with Serena Williams's cell phone voice-mail record. Her previous high was seven messages, but when Williams checked her phone late on the night of Sept. 11, she sensed that a new era had dawned. "Oh, my God!" she cried with joy. "I got 18!"

Behind the surge in wireless tidings was Williams's thrilling victory in the women's final of the U.S. Open in New York City. Powerfully built at 5'11" and 145 lbs., Williams—who turns 18 on Sept. 26—beat the always efficient but apparently fatigued No. 1 seed, Martina Hingis, becoming the first black woman to win the Open since Althea Gibson in 1958, and the only African-American besides Arthur Ashe to win a Grand Slam singles title in the last quarter-century. Along the way, Williams's exuberance enchanted the crowds—so much that even before the finals a star had clearly been born. "She's Jordan-esque," gushes CBS tennis analyst Mary Carillo. "The smile, the confidence, the way she carried herself—she plays like she knows she belongs."

Perhaps the biggest upset was that Serena became the first Williams sister to take home a major title—her older sister Venus, 19, having lost to Hingis in a grueling three-set semifinal the day before. "Venus was definitely bummed, because she wanted to win," says Serena. "But it gave me even more motivation, because I could win for both of us." A day after Serena's triumph, the sisters teamed up to claim the women's doubles title and celebrated by catching an evening showing of the ghostly thriller The Sixth Sense.

Things started to seem a little surreal for Serena as she made the rounds of the morning talk shows the following Monday. In the Today green room, her new Jack Russell terrier Bala—named for Enrique Iglesias's "Bailamos," a favorite song—jumped into the lap of fellow guest Pat Buchanan. (He didn't mind.) Later, Serena volleyed with Today anchor Katie Couric on a makeshift court and lost a thumb-wrestling showdown with Rosie O'Donnell. Then there was the call from President Clinton, phoning from New Zealand. "What?" said a shocked Serena when told he was on the line, before admitting to Clinton that she was "pretty stoked" by the call.

She also chatted with Chelsea, though the two didn't discuss their occasionally embarrassing fathers. Outspoken Richard Williams, 57, had spiced up the Open by brashly predicting an all-Williams final, which some critics felt put undue pressure on his daughters. In fact, Richard and his wife of 27 years, Oracene, 47—who have three older daughters—have been exceptionally nurturing tennis parents ever since he envisioned his dynamic duo in 1979, after seeing a female player win $48,000 on TV. "I told my wife that we had to have two more girls and make them tennis players," Williams explained.

Raised in the gang-ridden Los Angeles suburb of Compton, where Richard ran a private security firm and Oracene was a nurse, Venus and Serena got their start on run-down public courts. "They were always-supernice, polite kids," says Rick Macci, their tennis coach from 1991, when the family moved to Florida, to 1995. "There wasn't a day they left practice without saying thank you." Venus burst onto the pro scene first and reached the finals at the 1997 U.S. Open, but it was the slightly less experienced—and less guarded—Serena who stole the glory this year. "Serena is a little more happy-go-lucky than Venus," says Macci. "She wears her emotions on her sleeve a little more."

She's also as nimble with a credit card as she is with a tennis racket. Serena likes to climb into her yellow BMW Z3—the one with the Tweety Bird antenna ornament—and cruise to her local mall, where she stocks up on lingerie from Victoria's Secret and goodies from the M.A.C makeup boutique (Ooh nail polish and Rocker lipstick are favorites). Still living with her folks in Palm Beach Gardens, Fla., Serena—whose total take at the Open was $915,000—is planning on moving into a home she and Venus are building nearby.

How her sudden leapfrog over her sister will affect the sweet dynamic between them—Serena claims they have not fought since she was 6—remains to be seen. But she was quick to credit her Open win to Venus's subtle exhortations from the stands. "In the second set, when I lost two match points, I looked to her before I looked to anybody else," says Serena. "And she was just amazing, helping me not to give up." Clearly, with that kind of sisterly synergy, no voice-mail record is safe.

Alex Tresniowski
Cynthia Wang in New York City and Lori Rozsa and Fannie Weinstein in Palm Beach Gardens