Pam Shriver had just beaten Martina Navratilova in the quarterfinals of the 1982 U.S. Open and she decided it was only appropriate that, at least this once, she indulge herself.

Shriver decided to let her celebration take the form of a big sandwich and a New York Yankees game. So she and two friends stopped at a fashionable delicatessen. On the way out, Shriver glanced at the check.

"Seventeen dollars? Wait a minute. That's a lot of money," she said.

Shriver's head for business, which caused her to review a check on the night of one of her most impressive victories, is a source of occasional humor on the women's tennis tour, but also one of respect.

It is almost as curious as her ability to play with constant pain, and her great patience despite having the profound bad luck to come along at the same time as two of the best players in the history of the women's game.

Shriver, who defeated Hu Na, 6-2, 7-6 (7-5), today to advance to the third round of the Open at the National Tennis Center, is not likely to be a finalist in this event when it concludes next week. She has been ranked among the top 10 in the world for the past five years but has made only one Grand Slam final in her career, when she burst onto the scene as a 16-year-old in the Open, reaching the 1978 final against Chris Evert Lloyd.

Shriver is scheduled to meet Anne Hobbs on Sunday in a match that is likely to be the last easy one of the tournament for her. Against Hu Na, the Chinese player who defected to the United States three years ago, Shriver barely avoided a third set, fighting off two set points and serving trouble resulting from weakness in her chronically injured right shoulder.

"I'm looking to my match against Hobbs, and after that things get a giant step tougher," she said. "I think I have to raise the level of my game a lot . . . "

Shriver, 23, has maintained a tenuous No. 4 ranking that sometimes has improved to No. 3 behind Evert, Navratilova and Hana Mandlikova despite a chronic rotator cuff injury to her right arm. Shriver is rarely without an ice pack on her shoulder or elbow.

Despite a recent three-month break from the tour, her shoulder is not recovered. According to some, it is perhaps most responsible for her inability to reach a final at a Grand Slam event.

"Pam has been in some kind of pain on and off for the last couple of years," said Mary Carillo, a USA cable-TV tennis analyst and former player. "It's rare that she can get through one week without pain. So, it's always going to be hard for her to win a two-week tournament because of that arm."

But at a time when other women players are succumbing to injury, stress and outright poutiness, Shriver is a thought-provoking example. As a break from the tour, she runs her own tennis club, which she helped renovate, near her home in the Baltimore suburb of Lutherville. She also is an art collector and recently renovated a 200-year-old townhouse near Baltimore.

"I need things besides tennis in my life," she said. "I like to have the tennis club. I like to have a say in where my money is going and how it's working for me. I think it's important, and I've always had this interest, but I have to learn the priorities. Obviously, tennis is first. But I think in the end it's going to give me a broader mind for what comes after tennis."

Shriver has also recently turned author. Long known as one of the most outspoken players, she has written a diary for the current issue of Sports Illustrated, another undertaking that helps her maintain her equilibrium on the tour.

Shriver addresses a number of issues from which most of the women players tend to shy from, including the increasingly frequent cases of stress and "burnout" among younger players, and the difficulty of getting a date -- "I guarantee you, Mr. Right is not hanging around any Best Western piano bar or Ramada video game room."

"The diary has become a hobby for me," she said. "I think it's good exposure for women's tennis. It's supposed to show the lifestyle and supposed to give a better idea of what we go through; the fact that we are people and have funny emotions and have sensitive times and good times and not so good times."

Although most of the diary is devoted to her own travels and problems with injury, she does not spare some of her fellow players. Included in the first of a two-part installment is an indictment of the new breed of young U.S. players -- "All the impressive players nowadays are from Europe. The young Americans show no imagination. They're Chrissie clones without her genius."

She also has some thoughts on Mandlikova, the occasionally brilliant but inconsistent Czech, who "can turn wacko when you're playing against her, but she seems wackier when you're with her." There also are some thoughts on Andrea Temesvari, the Hungarian beauty, who "spends more time putting on makeup than the rest of the girls combined."

Shriver's frankness is equaled only by her sense of timing. She invited potential criticism from her fellow players by agreeing to its publication during the Open.

"I'm sure a couple of people will say, 'What did you say that about me for?' " she said. "But I'm honest."