There were two upsets yesterday at the Smith Center. In the one that really mattered, Sylvia Hanika, the sixth seed, outlasted Andrea Jaeger, the second seed, 6-7 (7-5), 6-3, 7-5. In the other, someone finally broke Martina Navratilova's serve. Twice. But Mary Lou Piatek could do no more and lost, 6-1, 6-3.

So, Hanika, who was the first of three women to beat Navratilova in 1982, will play Monday night at Capital Centre in the final of the Virginia Slims of Washington tennis tournament.

Jaeger, who is 17 and ranked third in the world, is unaccustomed to a player being stronger than her in the third set. Especially a player who is 23. But Hanika was. Jaeger led, 5-2, and served for the match at 5-3. Then she was betrayed by her own unforced errors (four in the game) and Hanika's strength. "The Redskins could have used her," Jaeger said. "Maybe Detroit could have. No offense against her, but she is built pretty strong."

"I was overpowering her," Hanika said. "I didn't give up. I think I surprised her."

Jaeger struggled throughout the tournament and last night was no exception. "In the beginning of the year and the end of the year . . . let's just say, in the middle I do better," she said.

She struggled back from 1-4 in the first set, largely on the strength of her forehand cross courts. When Hanika got in trouble, as she did in the tiebreaker, falling behind for good, 3-2, it was usually because she was winding up on her forehand and overhitting it.

She did better in the second set, mixing up the pace, with spins and drop shots that brought Jaeger in from the baseline and broke her in the seventh game. She saved two break points to win the final game of the set and stormed into the third, breaking in the first game.

Then Jaeger got lucky. At 30-15 in the fourth game, Hanika served what looked like an ace down the middle. Tour referee Lee Jackson, who was in the chair, ruled the point should be played again. Jaeger passed with a high looping backhand and went on to break. The set was tied 2-2.

The she broke again in the sixth and held in the seventh and led, 5-2. Then two things happened. Unasked by Jaeger, the tour trainer, came out to offer her antacid tablets. Jaeger had a bad stomach. "Don't make it look like, 'Jaeger has an upset stomach and Hanika upsets her,' " she said.

"She raised her game and I let her get away with it."

Hanika began rushing the net, forcing things, forcing errors. Jaeger made them in part, she said, because she was going for more things (she even made two drop volleys in one game, which almost made her night). "You can't play your whole life at the baseline and wait for someone to drop dead there," she said.

Hanika was not ready to roll over. She broke to make it 5-4, held to tie at 5-5 and then broke again to lead 6-5. Twice in the game, Jaeger saved break points, once with a marvelous forehand cross court winner, only to lose it when a backhand went awry.

Still she had another chance. Hanika served for the match. At 40-15, her nerves got the better of her. Two match points escaped her. Three unforced errors gave Jaeger a break point and a chance to send the match into a deciding tie-breaker. But a strong forehand cross court deep in the corner sent Jaeger running and her forehand wide. On the third match point, a big strong serve, as big as the win, kicked in to Jaeger's backhand. She netted it.

Navratilova has yet to play a seeded player. Such is her domination these days that players, like Piatek, find themselves behind, going for winner, making too many errors.

"They think they have to make a great shot," Navratilova said. "They think if they play their game, it's not good enough. If they try to go for too good a shot, they may get away with it."

More often they don't. "That's where they get beaten," she said. "They make unforced errors."

Navratilova was mildly perturbed with a few of her own unforced errors, which cost her a break in the third game of the first set.

Piatek was surprised that Navratilova elected to stay back as much as she did on her serve, and was surprised at the steadiness of her ground strokes. But there was method in Navratilova's thinking.

"It's a lot easier to stay back and make them (Piatek's returns) into passing shots," she said. "She hits it so short, you're always picking it off your shoelaces. When I got a good serve in, she could not make a good return. But if my serve was mediocre, where she could pounce on it, she was hitting it right at my feet and I had to volley up. Then she got easy passing shots. So I was mixing it up. That's my advantage now."