Martinez Joins Upset Victims : Tennis: Top-seeded player and Wimbledon champion is beaten by Amy Frazier in straight sets; Novotna, Garrison-Jackson also bow out.

Now who’s left in the Virginia Slims of Los Angeles?

Joining Martina Navratilova on the sidelines Friday was top-seeded Conchita Martinez, who was upset by Amy Frazier in the quarterfinals before 3,500 at the Manhattan Country Club in Manhattan Beach, 6-4, 7-6 (7-1).

Frazier will play Sabine Appelmans of Belgium in today’s semifinal, after Appelmans upset fourth-seeded Jana Novotna of the Czech Republic, 6-4, 4-6, 6-4, further depleting the field.

Seventh-seeded Julie Halard of France, the highest seeded player left, and Ann Grossman will play in the other semifinal. Halard beat Patrica Hy, 3-6, 6-2, 6-4, and Grossman defeated fifth-seeded Zina Garrison-Jackson, 3-6, 7-6 (7-5), 6-2, in a 2-hour 36-minute match.

After losing Kimiko Date, Lindsay Davenport, Mary Pierce, Natalia Zvereva, Gabriela Sabatini and Lori McNeil, all of whom dropped out before the tournament because of injuries, the event lost its

marquee players to unheralded opponents.

Navratilova was ousted in the third round Thursday by Grossman. Perhaps even more surprising, however, was Frazier’s victory over Martinez, the Wimbledon champion ranked third in the world.

Martinez, from Barcelona, improved her baseline game this year as well as her fortitude. She became the first Spanish woman to win Wimbledon, defeating Navratilova in an emotional three-set final last month. By doing so, Martinez helped dispel the idea that Spanish players are nothing but clay-court specialists.

And after routing Elena Likhvotseva in the third round Thursday night, 6-0, 6-0, Martinez seemed likely to cruise into Sunday’s L.A. final.

But the impeccable game of Thursday was missing Friday and Martinez was vulnerable against Frazier, 21, of Rochester Hills, Mich.

Ranked 26th, Frazier has had a modicum of success. She reached the quarterfinals of the Australian Open in 1992, but has been unable to find the consistency to crack the top 10 rankings.

Last year, Frazier spent six months struggling with health problems. She did not come back strong. This summer, she lost in the first rounds of the French Open and Wimbledon.

Those humbling experiences, among others, have quelled her emotions. Instead of exulting, Frazier said of her victory, “This is (simply) one match.”

It might not be a breakthrough, but it was the biggest victory of her season. After taking a 3-0 lead in the second set with two breaks, Frazier faced a stiff challenge.

Using her loopy topspin strokes to mix up the attack, Martinez won four consecutive games for a 4-3 lead. But Frazier served well to hold, and then did not falter.

Martinez was caught off guard.

“I thought I would pull it out,” she said.

It was not about to happen. The players held serve to force a tiebreaker.

Then, Martinez had little fight when it counted most. She fell behind, 5-0, when she mis-hit a forehand, hit a drop shot wide, a deep backhand wide, another backhand into the net and a forehand long after Frazier’s nice service return.

“You just have to appreciate (her play),” Martinez said. “She played unbelievable. She was pushing me. I was all the time on defense.”

Whereas Martinez saw something special in her opponent’s game, Frazier was not quite sure how she did it.

“I don’t know,” she offered.

Frazier does know that if she wants to become a force on the women’s tour, she must improve her serve.

“It needs quite a bit of work,” she said.

Navratilova once said of Frazier: “She hits the ball hard, so you really have to be ready for her. If she served better, she’d be really dangerous.”

Whether that ever happens remains to be seen.

Frazier, 19-11 this year, lost to Martinez in the third round of the Australian Open, 6-3, 6-0. But Friday she was able to pressure Martinez into uncharacteristic errors by playing patiently.

“Sometimes, I try to hit a winner too early,” Frazier said.

Frazier tried to jump-start a career early by skipping college. She had seven national singles titles to her credit as a high school junior. During those days on the junior circuit in the Midwest, Frazier got to know Grossman, from Grove City, Ohio.

It was not until 1991 and ’92 that Frazier gained some attention by reaching the fourth round at Wimbledon.

Since then, she has to be satisfied with defeating someone of Martinez’s caliber even in a minor tournament.

And enjoy it as well.