Tracy Austin, the relentless child of tennis, advanced to the semifinals of the U.S. Open Championship today by battering away at the backhand of Sylvia Hanika until the West German's game was in windy shreds, 6-1, 6-1.

The 16-year-old in the pink dress, who has The Future of Women's Tennis written all over her, showed the hallmark of her game -- a single-minded tenacity once she has seen a tactical path to victory.

The victory put Austin in the semifinals against second-seeded Martina Navratilova, who easily defeated Kerry Reid, 6-4, 6-1, in an evening match.

The night before, Austin, ranked No. 3 in the world, had feared the Hanika confrontation, a rematch of the Italian Open final, enough to default her doubles match on the Stadium Court just minutes before it was rescheduled.

"I had a headache and felt so bad I thought I would throw up," said Austin, who had come within two points of losing to Kathy Jordan in the match that carried her to the quarterfinals.

"The Jordan match just drained me," said Austin, who also reached the semis at Wimbledon in July. "My body was run down. I just stayed by the phone hoping that the rain (the remnants of Tropical Storm David) would come and I wouldn't have to default.

"I figured I might as well give myself the best chance. But the rain wouldn't come."

Austin's fear was that a doubles match into the morning hours on top of her Jordan ordeal might leave her too drained to handle the sturdy 19-year-old Hanika -- a left-hander with a truly Teutonic windup on her powerful forehand, serve and overhand.

Austin need not have worried. Hanika, a bouncy Lesley Hunt lookalike for physique, has her strengths, but she also has a trace of a weakness -- a predictable defensive slice backhand. Against Austin, that is like offering steak to a tiger.

Hanika won the first game of the match, but Austin quickly discovered that whenever Hanika tried a straight backhand drive or a topspin backhand, it ended up in the net.

In addition, the swirling winds that delayed play today for more than two hours turned Hanika's high service toss into a nightmare.

"Sylvia takes a big swing on her forehand and on her serve," said Austin, playing a "gee, I don't hit it very hard" role. "The ball has a lot of chance to wiggle around (in the air) before she hits it."

Again and again, Austin drilled her precise and deep groundstrokes at Hanika, turning the 5-foot-6, 130-pounder into half of a metronome -- a toy that raced from the middle of the baseline to its right and back, over and over.

Austin won the next 11 games. By the time Hanika finally won her only second-set game, the sparse crowd was giving her encouraging cheers. In fact, Austin wrapped up the second set in only 21 intensely purposeful minutes.

As if Austin needed any more help, the stadium was an echoing chamber of distractions with the hissing wind blowing trash across the court and creating a constant timpani roll of soda and beer cans being blown down concrete steps.

Hanika looked annoyed, while Austin, Miss Pigtailed Concentration, saw the noise as merely an extra edge for her.

Austin, playing in the great events at Wimbledon and here for the third year, clearly is aiming for nothing short of a spectacular dethroning of tennis' queen and princess, Chris Evert, who has won the U.S. Open four straight years, and Martina Navratilova, the world's No. 2 player.

Austin hardly fears the prospect of facing Fortress Navratilova, the 145-pound Czech blaster who is as strapping as the 5-foot-3, 103-pound Austin seems dainty.

When Austin and Navratilova met at Wimbleton, the big southpaw won so easily that, by the end of the last set, Austin simply looked up into the crowd at her parents and gave them a "well, it's not my day" smile.