On Sept. 20, 1973, top women’s tennis player Billie Jean King defeated former No. 1 ranked men's tennis player Bobby Riggs in a "Battle of the Sexes" match.Watch the video above for moreKing beat Riggs in straight sets, 6–4, 6–3, 6–3.More than 30,000 people attended the match at the Houston Astrodome, and another 90 million people worldwide watched it on TV. It is still considered one of the most watched televised sporting events of all time.Riggs, who was 55 years old at the time, was a self-described male chauvinist who said that the women’s game was inferior to the men’s game. He also claimed that he could beat any female player, even at his age.On May 13, 1973 — a few months before the famous tennis match with King — Riggs challenged and defeated female tennis player Margaret Court 6–2, 6–1. After previously declining his offer, King accepted his challenge and agreed to play him in the "Battle of the Sexes" match.Video below: Billie Jean King Talks About Sexuality And EqualityShe felt pressure to win, saying after the match, “I thought it would set us back 50 years if I didn’t win that match. It would ruin the women’s tour and affect all women’s self-esteem. To beat a 55-year-old guy was no thrill for me. The thrill was exposing a lot of new people to tennis.”Throughout her tennis career and beyond, King advocated for women's equality and fought for equal prize money for male and female players. King’s victory helped legitimize women’s tennis and is often credited for empowering women to advocate for equal pay in all sectors of the workforce. The historic match was the subject of a 2017 movie titled "Battle of the Sexes," starring Emma Stone, who played King, and Steve Carell, who played Riggs.