The low-hanging sun was just beginning to warm the red-clay practice courts at Racing Club, a chic facility near Roland Garros, but Kathleen Horvath already sensed something remarkable was in the air.
Two weeks earlier, the 17-year-old from Chicago had reached the semifinals of the Italian Open. And although she lost there to 14-time Grand Slam singles champion Chris Evert, earning two unlikely match points gave her an unprecedented confidence. Now, grooving groundstrokes, Horvath found herself in one of those rare, inexplicable zones.
"It was one of those perfect days you can count on one hand," Horvath remembered. "I woke up feeling great and when I started warming up I felt perfect, like I could put the ball on a dime."
Her fourth-round opponent on May 28, 1983, was in the midst of perhaps the most dominant stretch tennis has ever seen. In the three seasons from 1982 to '84, Martina Navratilova would win 254 matches -- and lose only six. The No. 1-ranked Czech player had won three of the previous four majors and all 36 of her matches to start the year.
"I wasn't thinking about the records while I was playing," said Navratilova, who again will be working as an analyst for Tennis Channel when the French Open begins Sunday. "But looking back, those are some pretty great numbers. That stretch of six losses in three years was pretty ridiculous."
This is the WTA's 40th anniversary and there has been a series of events commemorating those four decades of rich history. Thirty years ago, a young American in Paris crafted one of the greatest tennis upsets of all time. This is the story of how she did it:
At Roland Garros, the venerable tennis venue in Paris' leafy southwest corner, the defending champion was expected to meet the No. 2-seeded Evert in the final. But no one factored the unseeded Horvath into that calculus.
The previous week, Horvath reached the final of the German Open at the Rot-Weiss Tennis Club in Berlin. In her sixth match in six days, she lost the final to Evert in straight sets on a Monday. Horvath, after traveling to Paris on Tuesday, easily won her first three matches at Roland Garros on Wednesday, Thursday and Friday.
"I thought for sure I'd have a day off Saturday," Horvath said. "But I was on the schedule. I really didn't have time to think."
Which was probably a good thing. Like so many tennis players when they're winning, she was a creature of habit. Horvath was staying at the then-Sofitel Hotel south of the tennis center. She would walk under the highway, head for the same Italian restaurant every night and eat osso buco for dinner and profiteroles for dessert.
Still, Navratilova said she was a little "tight" when she stepped on the court that day seeking her 37th consecutive victory of the season.
"Chances are, if you play your normal tennis, you win," she said. "And if I didn't, well, I would make headlines just by losing. It puts pressure on you to win every match."
Horvath, who was a steely, cerebral player for someone so young, was oddly confident. She actually liked her chances on the world's largest court. Horvath had played on Court Central three years earlier -- it would not be named in honor of Philippe Chatrier for another 15 years -- beating Californian Kelly Henry in the junior girls' final at the age of 14. And, underneath Navratilova's muscular bravado, Horvath sensed a weakness.
"I felt she could be rattled," Horvath said. "This is going to sound bad, but every player has their tendencies. I always thought if you could start well against Martina you might have a chance because she was not the most inherently confident person."
On faster surfaces, Horvath said, it didn't matter because Navratilova's big lefty serve was too much. When a short ball, inevitably, came back, she was all over the net. But on the cloying clay, Horvath had a split-second longer to survive that serve, get the ball deep and find her way into the point. Australian Harry Hopman, her coach, was never quite that specific. "Hustle," he used to tell her. "Hit for the lines."
Horvath walked on the court wearing a Fila navy-blue shirt and white skirt that she had made her mother hand wash every night since the beginning of the German Open. The shoes were by Pony and her racket was a Prince woodie with synthetic gut strings. Ordinarily Horvath, at 5-foot-6½, 120 pounds, was a steady baseline player. On this day, however, she moved forward at every opportunity.
Hitting her spots precisely, Horvath won the first set 6-4.
"Man, I just couldn't relax," Navratilova said. "I couldn't get the ball past the service line. I think if I could have gotten ahead it might have been different. But I couldn't shake her."
Still, Navratilova rallied to win the second set at love.
"When I won the first set, I said, 'OK, I'm going to win this match,'" Horvath said. "Then I lost the second set 6-0. I told myself, 'Relax and play like you did in the first set.'"
They split the first six games of the third set, but Navratilova's coach, Renee Richards, and trainer, Nancy Lieberman, could be heard arguing in the players' box about strategy. Navratilova heard them, which couldn't have helped her state of mind. The pattern that emerged: Horvath would hit a deep groundstroke and Navratilova's chipped backhand would fall short. Horvath would jump on it with a slice approach and, even though the ball was deep, Navratilova would hit her own approach shot, then hesitate when she realized she was too deep. Horvath finished a number of points with a swinging, sharply angled volley.
"I actually remember match point," Horvath said. "I came in to net and she hit a backhand. But she wasn't in a position to hit a passing shot and she missed. Everything was turned around on her that day."
The final score: 6-4, 0-6, 6-3.
To be honest, Horvath felt more relieved than elated. She remembers the photographers rushing the court. Horvath was not overly demonstrative on the court, but they coaxed an awkward and atypical thumbs-up from her and a variety of smiles.
Navratilova congratulated Horvath at the net, but was furious with herself afterward.
"I didn't mind losing," Navratilova said, "but I really didn't want to lose then."
It would be her only loss to Horvath in 11 career matches.
Horvath's victory created a rippling buzz throughout Paris. And, because she had Sunday off -- and was a 17-year-old reveling in what would turn out to be the match of her life -- Horvath said yes to every single media request. There were lots of interviews and photo shoots among the flowers of Roland Garros and at the Eiffel Tower. Since she had taken down the world No. 1, the stories said, she had an easy path to the final against Evert. The opponent in the quarterfinals was unseeded Mima Jausovec with, perhaps, unseeded Jo Durie waiting in the semifinals. Since Horvath had very nearly beaten Evert in the Italian Open, it was reasoned, she could conceivably win the tournament.
"The whole day, I'm having a blast," Horvath said, "but in the meantime I'm losing my focus, letting down my guard."
Yugoslavia's Jausovec, who had won her only major six years earlier at Roland Garros, beat Horvath 6-1, 6-1.
"She just didn't make many errors," Horvath said. "If you are off, you could easily beat yourself, and that's what happened."
Jausovec would go on to lose to Evert in the final.
It was a huge upset at the time, but as the season progressed it became even bigger. For Navratilova would go on to win her final 50 matches of the year. That jarring loss prevented her from achieving a perfect season. Her 1986 season, which featured three Grand Slam singles titles, is considered by historians to be among the best in history.
Perhaps the very best? When Steffi Graf won the Grand Slam in 1988, she went 72-3. The year Rod Laver won all four majors as a professional, in 1969, he lost 15 matches. In Roger Federer's best two seasons in terms of won-loss percentage, 2005 and 2006, his records were 81-4 and 92-5.
"I don't know," Navratilova said. "If I hadn't lost to Kathleen Horvath that year, I might have lost to somebody else. That was only May. You know, the pressure just builds and builds.
"Maybe my two-loss year  was better."
For Horvath, it was the high-water mark of a career. She again reached the quarterfinals at Roland Garros the following year, but never matched that accomplishment in any other major. In the spring of 1989, still only 23 years old, she lost in the first round at Amelia Island.
"I saw some older players who had lost in qualifying running wind sprints," Horvath remembered. "They looked old and miserable. I said to myself, 'I don't want to be that.' Back then it was very much the mentality to be driven 100 percent. Well, that's just not sustainable."
And so she quit. She eventually earned two degrees from the University of Pennsylvania, graduating magna cum laude, and worked on Wall Street. Today she lives in New Jersey with her husband and three children, one of whom is already a nationally ranked player at the age of 13.
Horvath introduced her son to the game, but no longer plays tennis.
"I feel like I had to do it for so many years," she said. "I like to do things I haven't done before."
In some ways, she said, that victory over Navratilova seems like it happened a long, long time ago. In others …
"Time flies," she said. "It gets fuzzy."
During a nearly one-hour interview, Horvath earnestly did her best to recount the match accurately. But sometimes there was an edge in her voice.
"She never really accepted it," Horvath said of Navratilova.
Told that in a recent interview Navratilova had fully credited her with the win, Horvath sounded surprised.
"Well," she said, "I'm glad she finally said that."
Years after that signature victory, Horvath and her 4-year-old daughter, Erica, ran into Steffi Graf in the players' lounge at the U.S. Open. Horvath introduced Graf to her daughter, saying, "This is the best woman who ever played."
Erica looked confused.
"But, Mommy," she said, "I thought you were the best player ever."
Graf, always gracious, smiled.
"You're right," she said. "Your mother was the best player."
For one day, at least, Erica Kathleen Horvath was.