It’s been a busy time for the USWNT. Within the span of 24 hours last week, they managed to win the SheBelieves Cup while firing back so thoroughly at the U.S. Soccer Federation’s misogynist views that USSF President Carlos Cordeiro resigned.

In addition to bluntly rejecting Cordeiro’s apology, Megan Rapinoe took the opportunity to address the underlying sexism of her industry. According to NewsChain’s Sarah Rendell, Rapinoe made a passionate appeal to her team’s fanbase, asserting “You are not lesser because you are a girl. You are not better just because you’re a boy.”

In the wake of this incident, Rapinoe and the USWNT found a very prominent ally in one of the all-time heroes of women’s and LGBTQ athletics…

Taking up the fight against ingrained misogyny is something Billie Jean King is intensely familiar with thanks to her triumph over Bobby Riggs in the famous “Battle of the Sexes” tennis match of 1973.

Leading up to the match, the 55-year old Riggs had taken on a public persona that combined the humanity of a pro wrestling heel with the decency of a morning radio shock jock. Riggs was infamous for finding the red light on any nearby camera and uttering smack talk like, “I’ll tell you why I’ll win. She’s a woman and they don’t have the emotional stability.” With that kind of language, he could’ve been named U.S. Soccer president.

As Rapinoe and the USWNT demonstrated, in today’s climate, Riggs would be rightfully shamed into contrition and would have probably lost work and endorsements. But 1973 was only a year after the passage of Title IX and an era when women’s sports weren’t taken seriously by many fans. Rather than relying on an outraged public, a prominent female athlete was going to have to make Riggs shut up.

Enter 29-year-old Billie Jean King.

In 1973, chauvinism came with its own endorsement deal.

On September 20, the two tennis stars squared off before an audience of 30,000 fans at the Astrodome and 90 million watching on TV. And while the camp factor of the match was played up with Riggs being escorted by a group of women he called his “Bosom Buddies,” King later admitted that something vitally important was on the line:

“I thought it would set us back 50 years if I didn’t win that match. It would ruin the women’s [tennis] 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.”

Fortunately, King thoroughly disposed of Riggs in three straight sets 6-4, 6-3, 6-3. In an era of sports where a woman had to prove that she deserved to be treated on equal footing with a man, she did so convincingly.

And what unites King and the USWNT today is that while this is something of a more enlightened time, some battles never change.