Don't let the word get around but Dianne Fromholtz, the plucky little lefthanded slugger from Sydney, Australia, won $98,210 last year with a tennis game that was almost a complete wreck.

At least that's what Fromholtz claimed last evening after she won an error-prone but tactically interesting quarterfinal match from crowd-favorite Kathy May, 7-6 (5-2), 7-5, in the Virginia Slims of Washington at Smith Center.

"I've had to go back to scratch with every stroke in my game and take it all apart," said Fromholtz, 21, who ranked 10th in the world last year.

"You just keep picking up faults over a six-month period until you're all in a mess. I had a big, erratic swing. I had no volleys, no approaches. I had no shots whatsoever running in toward the ball.

"And my serve wasn't much either."

How did she get the ball over the net last year?

"Sometimes I don't know," the 5-foot-4, 124-pound Fromholtz, who has always been a baseline blaster, said with a grin.

If two months of drastic revamping have helped Fromholtz, then she should also thank May for aiding her yesterday.

May, down a break in the first set, fought back and broke the Aussie twice, finally taking a 6-5 lead and serving for the set. But in her moment. She lost her serve at love, starting with three hair-pulling unforced errors in a row.

"I just didn't have the concentration I did when I beat Virginia Wade (on Wednesday)," said May. "Maybe three matches in four days wore down my intensity."

May, 21 and an heir to the May Department Store fortune, took a 2-1 lead in the tie breaker, then fell asleep again with two errors while trying to place the ball precisely as she tried to jerk Fromholtz off the court. The Australian ran off the last four points of the set.

May's margin of error is always slight. She mixes her pace, picks her spots to go for service winners or to charge the net. But yesterday Fromholtz took away May's best weapon - her accurate, medium-speed passing shots - by seldom coming to the net unless success seemed certain.

May was kicking herself again in the second set, too, when she broke through for 2-0, fell back to 2-2, then broke again for 4-2. But her icy poised cracked as she netted two backhand volleys and butchered an overhead as the crowd moaned at watching her break her serve.

May's best tactic was to charge the net on crucial must-win points. Time and again Fromholtz seemed surprised and overanxious as she hit the net cord with blistering backhand passing shot attempts.

But in the ninth game of the second set. Fromholtz was ready and handcuffed May at the net twice for a break.

Then May made one last courageous stand, like the ones that won her the fans, approval in her Wade upset. She fought back to 5-5, breaking Fromholtz at 15 with a ringing volley.

But that old demon lob undid May in the crucial 11th game. On game point for a 6-5 lead, she swung so early than her awful overhead hit the bottom of the net. The Smith Center buzzed.

Before she got her head straight May had made two quick errors and was on the way to losing nine of the last 10 points of the match.

"We were both going off and on all night," said Fromholtz, who plays top-seed Martina Navratilova, winner over Greer Stevens, 6-2, 6-3, in a 45-minute quarterfinal romp, in Saturday's 1:30 p.m. semifinal.

"The thing this tournament has shown is the way a player has to fight to get to the semifinals of every tournament now," said Fromholtz. "Two years ago the good players waltzed through the early rounds, 6-1, 6-0. Now the girls hate to quit. They win a set, force tie-breakers. It's better tennis, but it's tougher on you."

May, who had not played since knee surgery following Forest Hills last year, was delighted with her two victories here. "I had a great tournament," she said. "Now I think I better go out and practice my overheads."

Navratilova, who won here in '75 and '77 and has never lost a match in Washington, continued to look superb. She pounded Stevens into the carpet with her big serve and service returns.

The almost perfectly proportioned Navratilova, who said in a joking way on Thursday that "I can't be beaten in Washington," was carefully getting her superstitions in order yesterday. "Of course, no one is unbeatable," she said, "I don't mean to say that. I just seem to play very well in Washington."

One of the reasons is that the Smith Center crowds root for her, an unusual occurance for a hard-hitting favorite.

Stevens, after her spanking, was almost awed by Navratilova. "She is moving so well that shots I thought were past her, she was returning, Stevens said. "That's kind of frightening when you consider all the power she has to start with."