If you thought Nora Ephron's "Heartburn" had cornered the market on true heartbreak, thinly veiled, make room for "Sudden Death."

Rita Mae Brown is the wisecracking, tough-talking author of "Rubyfruit Jungle" and "Southern Discomfort," and her romance--with tennis star Martina Navratilova--went sour when Navratilova: a) went off with another woman or b) just got tired of Brown's company, depending on whose version you accept.

Don't get mad; get even, as the saying goes, and this novel should bring the score to deuce. It not only chops the stars of women's professional tennis down to size; it tackles the whole pro tennis establishment--the sponsors, the fans "in the inevitable Lacoste shirts," the college groupies in their sneakers and the cocktail parties, where the players "showed up when the main sponsor wanted their a---s there," and "shook the hands of bank presidents, furriers, car dealers, and other businessmen too exciting to mention."

Having reduced that tableau to rubble, Brown turns her guns on America's intolerance of lesbians.

That's a lot of targets for one bombing run, and all 241 acerbic pages of "Sudden Death" are jammed with as disagreeable a bunch of people doing mean things to each other as you are likely to meet at one time, even in rush hour.

Everything in the book is "merely illustrative and entirely imaginary," of course. But you can wallow in titillating parallels all you want. At center stage, for a start, we have Carmen Semana, the foreign-born tennis star and her wisecracking, tough-talking lover, Harriet, whom she ultimately abandons for a groupie in sneakers.

It is hard to imagine what the observant and mordant Harriet ever saw in Carmen, even when the bloom was on the rose. Carmen has a thimble-sized mind, a nasty temper that she vents on linesmen, waiters and cab drivers, who can't fight back, and is sulky and spoiled. "If she wanted a glass of orange juice," Harriet reflects, "someone else picked, shipped, then squeezed the orange. Carmen squeezed life, and she thought there would always be juice." She eats steak, pasta and coffee for breakfast, while Harriet settles for a Coke. In a moment of blinding clarity, Harriet decides that "Carmen is the only man I've ever loved."

Women's professional tennis, as the tale unfolds, is a self-contained traveling jungle. From Kansas City, which "rose out of the plains like an act of human imagination," to Chicago, which "hung on Lake Michigan like a glittering choker," to the lands beyond the seas, no grass grows where this joyless caravan has passed. The players have skins of leather and hearts of zinc. You'd be safer with some Gaboon vipers on the L-2 bus.

Given some of the men they have to deal with--scheming, dishonest and gross--you can see how some of these women might go off into the sunset hand in hand with other women. But their loves seem built on sand, and changing partners is written into the dance. Their twisted and broken entanglements lend venom to their encounters on the court. The final crescendo pits Carmen against Susan Reilly, her archrival and former lover. (Susan's current partner, Alicia, a "terminal prude," sneaks off and gets pregnant by another player's coach, "who never had an idea above the waist" . . . And so it goes.)

These dramas are open secrets in the tennis world. But to the tournament organizers, "America isn't ready for a lesbian scandal in women's tennis." It could scare the sponsors away, and if they go, the whole shaky structure will collapse. Harriet proclaims, "If you're ashamed to be lesbian, you're ashamed to be a woman." But she is overwhelmed by events, and somehow you don't much care.

The book is rich in pungent generalizations. "Women who've graduated from Pappagallo shoes to Geoffrey Beene like places like Hilton Head," Brown notes at one point. "The wildlife and quiet controlled surroundings help these women and their husbands in madras pants to surrender to a few moments of pinched rapture." The English, she remarks, as the scene shifts to Wimbledon, "have a natural impulse toward kindness and spend the rest of their lives brutally restraining it."

The irony is that the individual people she portrays only fitfully resemble humans--let alone the Real People that the much publicized circumstances behind the book would lead you to expect.