50 years ago today, one sporting event changed my life. In fact, it changed everything.

Fifty years later, I remember exactly where I was sitting that night in the family room of our home in the Toledo suburbs. I can see my parents in the room, and my three siblings.

Had someone asked us then if people would remember that evening 50 years into the future, I think we would have thought, yes, that was possible. The Battle of the Sexes was that important to us and to everyone else we knew.

On the evening of Sept. 20, 1973, Billie Jean King, 29, one of the greatest women’s tennis players of that or any era, took on tennis hustler and self-described "male chauvinist pig" Bobby Riggs, 55, in a massive spectacle in the Houston Astrodome televised live on ABC. There were only three or four television channels to pick from back then, so when a big event like this aired, the audience was vast and the impact was immediate.

For days beforehand, the match was all we talked about in school. The allure, of course, was the coast-to-coast spotlight that was soon to shine on the age-old rivalry of the boys against the girls. But this was more than that. Never before had I seen a woman share a national stage with a man as an equal — in sports, or in any segment of our society. This was about Billie Jean vs. Bobby, but it also was about millions of girls like me, ready to be launched into what was to become a different and far more open-minded America.

Our gym teacher and coach, Sandy Osterman, had us all worked up over the match. In gym class or at practice, if a boy walked by, she’d yell, "We know who’s going to win!" The boy often smirked, rolling his eyes at the thought that a woman could beat a man in anything.

There were side bets worth all of a few dollars between Miss O, as we called her, and her male coaching and teaching counterparts.

"We’ll see who wins," she’d say with a mischievous laugh. We girls smiled along with her, and we wondered: What if Billie Jean actually beat him?

King was the perfect person to take on Riggs. She ruled women’s tennis in the 1960s and 1970s with a demeanor on court that was a startling departure from that of the more demure women who populated the game. To see a female athlete who was so aggressive on the court, and off, was a revelation. Less than two weeks earlier, in an unprecedented move that reverberates to this day, the 1973 U.S. Open paid the women’s champion the same prize money as the men’s champion, almost entirely because of King’s advocacy.

As a young tennis player myself, I wore a tennis dress that looked like the kind King wore, sleeveless with a zipper up the middle and a big striped collar. I was so enthusiastic about the game that my family took a small black-and-white TV set on vacation with us to northern Michigan every year so I wouldn’t miss Wimbledon.

That night, it was a carnival atmosphere when Billie Jean and Bobby came onto the court — she on an Egyptian litter, he on a rickshaw — before a crowd of more than 30,000 in the Astrodome and millions more watching at home.

Riggs, who had easily defeated another top player, Margaret Court, four months earlier, played the scene for all it was worth, wearing a yellow warm-up jacket with the "Sugar Daddy" logo while King joined right in, presenting Riggs with a live piglet wearing a pink bow.

Before the match began, my father pointed out the subtlety behind Riggs’ over-the-top bravado. "He’s acting bad, but in some ways, he’s just playing along," my dad said. "He’s the perfect opponent for Billie Jean. He makes you want her to win even more."

As it was, I already wanted her to win very badly. Billie Jean King was one of the very few female sports heroes I had.

It turned out there was no reason for me to worry that night. Billie Jean ran Bobby all over the court and easily defeated him, 6-4, 6-3, 6-3, throwing her wood racket into the air as we cheered in the family room. It was the first time I had ever seen a woman beat a man in anything.

"It was the night that changed my life forever," King told me as we worked together on her 2008 book, Pressure is a Privilege. "No matter how many matches I won in my long career, the Battle of the Sexes stands out not only for its fame, but also for its instructiveness. That match taught me more than I could have ever believed."

You can imagine what happened the next day at school. Miss O was ebullient, collecting on all her little bets as we girls cheered her on. Meanwhile, in the hallway, I passed a boy in my grade who played sports as I did, both of us on a variety of teams.

"We won," I said to him. "The girls won."

"Yeah, I know," he said, grimacing and walking away.

In the many years since, men have occasionally told me they thought the Battle of the Sexes was one of the most overhyped sports events of all time, a silly exhibition, nothing more.

I always disagree. "For you, maybe, but not for me."

Billie Jean and I have known each other for more than 30 years, but no matter when or where we talk, I always make sure to thank her for what she did that night in Houston. It’s surely overkill by now, but I can’t help it.

"What you meant to a girl growing up playing sports in Toledo, Ohio…"

I never complete the sentence. She knows.

This article originally appeared on USA TODAY: The Battle of the Sexes: Billie Jean King win matters 50 years later