PHILADELPHIA -- Monica Seles drives a tennis ball the way a truck driver handles a rig -- with two-fisted power -- and anyone in its path better get out of the way.

On each point, she grunts like a dockworker unloading heavy cargo. During Wimbledon, a London tabloid rented a noise meter and placed it on the court during a Seles match. She was louder than rush-hour traffic, the meter said. And a lot more dangerous, her opponents might add.

At 16, Seles, in the last year, has powered and grunted her way from a ranking of No. 88 to No. 3. She became the youngest winner of the French Open in June and has career earnings of more than $1 million.

Surprising, even to herself, Seles is a legitimate challenger to Steffi Graf, ranked No. 1 for three years, whom she has beaten twice this year, including in the French final, and No. 2 Martina Navratilova.

In a year, Seles has grown from a petite 5 feet 4 to a 5-9 1/2, size-10-shoe athlete who doctors predict will top out at 6 feet. While finding the growth spurt somewhat disconcerting -- "It changed all the angles. And I don't want to be 6 feet tall," she wails -- Seles has used her new size to add even more power to ground strokes that were already the hardest on the tour.

"If she ever develops a serve," Navratilova said, "the rest of us can quit."

And with a contagious giggle that is reminiscent of Woody Woodpecker, plus that grunt, which entertains the fans, though it annoys some opponents, Seles, along with 14-year-old phenom Jennifer Capriati, has inherited the crowd support that Chris Evert once commanded.

Born in Novi Sad, a small town in northern Yugoslavia, Seles didn't know much about great champions at first. Her father, Karolj, a cartoonist, tied string to the bumpers of two cars and used it as a net when 6-year-old Seles wanted to play tennis because her brother, Zoltan, did.

By the time she was 7, Seles had retired. "I just decided, 'I don't want to do this anymore,'" she recalled. But by the time she was 7 1/2, and after seeing Zoltan bring home big trophies that impressed the neighbors, Seles picked up her racket again. For good.

To make practice fun for his bubbly daughter, Karolj painted the faces of the cartoon characters, Tom and Jerry, on tennis balls. Or he lined up stuffed animals along the baseline. The ones Monica hit, she kept.

By the time she was 9, Seles won the Yugoslav 12-and-under title, even though she didn't know how to keep score. When his daughter would ask during matches how she was doing, Karolj would say: "Hush. You will find out at the end."

Three years ago, realizing that the concrete courts of Novi Sad were not good for his prodigy, and having attracted the attention of Nick Bollettierri, Seles moved his family to Bradenton, Fla., and the Bollettierri camp. There, Seles improved on her unorthodox two-handed forehand, and her backhand, and became Americanized.

"I learned English from watching 'Jetson' cartoons," she said. In fact, the family dog is named Astro.

Now that she is of driving age, Seles longs for a Lamborghini: "Red, of course. And it would be nice for my brother too. He would sleep in it, maybe. My friends want me to get one also. They would look so cool riding with me in it."

So far, though, Karolj and Monica's mother, Esther, have held up the purchase of the red Lamborghini. "I've been shopping for one though," Seles sighed.

She is not without wheels, however.

For example, one interviewer got a call from Seles from the car phone in the limo that was taking her to the Burbank, Calif., studios of the "Tonight Show." Seles wowed Johnny Carson by wearing a black-and-white minidress, elbow-length gloves and high heels. Seles looked like an ingenue, not the coltish teen who still traveled with stuffed animals.

Also in the American way, Seles and her father decided to drop Bollettierri just before the French Open. It was an acrimonious parting, with Bollettierri threatening to sue for $200,000 in expenses he said the Seleses owed him.

But Monica was hardly fazed. "My father, really, was always my coach," she said. "Of course, Nick helped me. But mostly it was my father. He is best for me. I am sorry Nick is unhappy, but this is best for me."

There can be no arguing that point. She's had a 36-match winning streak that ended with a tense, three-set quarterfinal loss to Zina Garrison at Wimbledon; since March 11, Seles is 40-1.

After Wimbledon, Seles took a month off. She returned to action two weeks ago at the Virginia Slims of Los Angeles and won her seventh title of the year, beating Mary Joe Fernandez in the semifinals and Navratilova in a three-set final.