(CNN)For Sarah Silverman, "Battle of the Sexes" was supposed to be something of a celebration.
'Battle of the Sexes' cast knows the equality fight rages on
Filmed during the presidential election, Silverman imagined the United States would have its first female president by the time the movie was released. She imagined watching the movie, about the infamous 1973 tennis match between female sports icon Billie Jean King and self-proclaimed male chauvinist Bobby Riggs, and feeling proud of "how far we've come."
"We got that smug smile wiped right off our faces," Silverman tells CNN. "Instead this movie has a whole new meaning."
In many ways, "Battle of the Sexes" still carries a hopeful air.
The film shows a 29-year-old King (played by Emma Stone) battling 55-year-old Riggs (Steve Carell) in a game of tennis that symbolically was worth so much more than the $100,000 prize on the table. She was fighting to prove that women were worthy of equal pay, to showcase the mighty strength of female athletes, and stand up to someone who embodied very antiquated ideals.
Prepare for a 44-year-old spoiler: She won.
The present proves, however, that many battles wage on for women.
"It's sad that it's still relevant," Carell tells CNN. "You know, you want to do a movie like this, and you want it to be a period piece. You want people to kind of nostalgically reflect back on, 'Oh my gosh, in the '70s, can you believe that there was any sort of attitude like this? Good thing that that doesn't exist today.' But it does. It's pretty heart wrenching that it's still a discussion."
Stone, who has spoken about her own struggle to achieve equal pay in Hollywood, agreed, saying to CNN the film should serve as a reminder that "one person can make such a huge difference."
"In many ways, it's pretty shocking to see how little has changed and how much we still need to move the needle forward," she says. "Progress can be slow, but it's so, so important to keep going, to not lose hope and to know that eventually, it'll all going to balance out."
To add a little more balance to the world, 21st Century Fox, parent company of Fox Searchlight, will donate a portion of "Battle of the Sexes" opening weekend ticket sales to the Women's Sports Foundation, which was founded by King.
The company said it will donate 79 cents from every ticket sold to WSF, a figure that represents the amount of money American women on average earn for every dollar paid to men, according to a release.
Carell was 11 years old when King and Riggs went head to head before 30,000 people at the Houston Astrodome -- and tens of million more around the world who were watching on TV.
"Even at 11, I understood the significance of this tennis match," Carell remembers. "But it didn't effect my perception because I was coming from a pretty open-minded place to begin with."
Carell grew up in what he calls a "equitable household." His mom and dad were equal breadwinners and "equal partners in child rearing." So he was raised seeing the world in that way.
He could also, he said, even see through Riggs' larger-than-life act.
"I could tell that he that it was a put-on," he says. "It was a big joke. And you could see, too, when Billie Jean and Bobby would do interviews together, there was a real affection that she had for him. So she knew. I think if she really believed that's what he thought, there'd be a different interaction between the two."
King ended up besting Riggs in all three sets (6-4, 6-3, 6-3).
Despite her victory, revisiting that time for this film was difficult for King -- "a lot of pain, a lot of joy," she says.
But did she, at the time, think the fight for gender equality would be won by now?
She responds swiftly, "no."
"One thing about being in your 70's, you have perspective. You know, at your age, I was like, 'Oh, let's go get this done in a few seconds,'" King says, addressing the 30-year-old reporter in front of her. "Well, not seconds, but 10 years, 20 years."
She balls up her fists while saying this, as if boxing in a fight with every naysayer and underestimator.
"You start to realize that every generation has to start over -- fighting for equality. And freedom and things go forward and then they go backward, they go forwards and they go backwards. It's just always in flux," she says. "It's really important that your generation and the younger generations take up the battle."