On one side of the net stood Eleni Rossides, the best 17-year-old amateur girl's tennis player in the entire mid-Atlantic region.

Across the net stood her opponent, hitting practice serves that sounded like artillery. She ruled her own tennis kingdom, one that covered a bit more turf.

"I almost fainted during warmups," admitted Rossides, a high school senior at Washington's Sidwell Friends who last night took on Martina Navratilova, the most dominant woman in tennis history, winner of more than $8 million in her career.

You knew it was going to be a rout. And after the second game, when Rossides broke Navratilova's serve, you were very glad to be wrong.

Last night at the Virginia Slims tournament at George Washington University's Smith Center, a young woman in a white tennis dress won five games from a legend. That's more games than many of the touring pros win against Navratilova in a year. The final score was 6-3, 6-2. Except for some nervous service mistakes by Rossides, playing in her first professional tournament, before 5,000 wildly partisan fans, it would have been closer.

"She has a good passing shot and she moves very well. She surprised me with that," said Navratilova, who hired Rossides' father Gene, a local lawyer, four years ago to help with her naturalization procedure. "Of course, she's 17. I moved well when I was 17, too."

Another local competitor, Alexandria's Kim Shaefer, also was eliminated from this $150,000 tournament yesterday, but in a less glorious way. Shaefer has a strong serve, good court sense and a passing shot that can rip a tennis racket from a vise grip.

But yesterday, playing against Bulgaria's top tennis export, in front of a gallery of family and friends, Shaefer was decidedly off, losing to Manuela Maleeva, 6-2, 6-1.

"I expected a lot more of myself today," said Shaefer, 27, who misfired nearly every shot in her arsenal against Maleeva, 17, the fourth seed. "I got just a little bit too frustrated today because I wanted to do so well."

Another player with something to prove, Kathy Jordan, fared better. After a three-month absence due to injuries, Jordan returned to the pro tour with a 6-3, 5-7, 6-4 victory over Sharon Walsh. For the eighth-seeded Jordan, however, it was a flawed debut.

"I was in trouble there. I was so stupid to let the (second) set get away from me," said Jordan, 25, who had won the first set and was up, 4-1, in the second when her serve began to stray. Walsh, 32, took advantage of Jordan's soft second offerings to break her service twice and win the set.

Jordan is a joy to watch, a quick, athletic player with a wicked underspin backhand and an intensity that is audible. She squeaks like a teapot at boil with every serve.

The current glamor girl on the women's tour, 17-year-old Carling Bassett, had a fairly easy time beating Mima Jausovec, 6-3, 6-3. Bassett seemingly has appeared on national television more often as a model or talk show guest than as a player.

But she was the tour's 1983 rookie of the year and is ranked 11th in the world. Her next match will be against Navratilova. "I'm going to pretend I'm not playing her, and just play the ball," said Bassett.

Most of the audience came rooting for upsets. For Shaefer, ranked 66th, to beat Maleeva, ranked sixth, would have been a big one. But except for early in the first set, when Shaefer rebounded from 0-3 to win two straight games, the match belonged to Maleeva.

Shaefer, who worked for two years in fast food emporiums before getting serious about tennis, says she is in need of another boost. "I expect a lot of myself in the next six months," she said. "I'm not going back to MacDonald's and Arby's."

For a few brief moments, after Rossides had broken Navratilova's first serve with powerful passing shots to tie at 1-1, the audience dared to hope. But never Rossides.

"It really didn't enter my mind," she said with a characteristic giggle. "I'm glad it's over."