Emma Stone and Billie Jean King are 45 years apart in age. Stone was born 15 years after King took down Bobby Riggs in three sets in 1973.

So when Stone showed up at the tennis icon's New York apartment to prepare for her upcoming role as King in Battle of the Sexes, the Oscar-winning actress mostly sat in awe. But soon, the two developed a friendly bond.

"She was very quiet," King says. "You could tell she was just really trying to absorb as much as possible. But over time, we text all the time, in fact, I knew about Margaret Court -- she's the one who texted it to me. I didn't even know it was even happening. I'm like, 'Emma sent that?' We've become much closer. It's gonna take time. I know she's be a friend now forever."

About a week ago, Australian legend Margaret Court claimed "tennis is full of lesbians" and expressed her opposition to same-sex marriage.

Stone, fresh off her performance as a dancer in La La Land, had to adjust to the role of a tennis star.

"I did actually go on the court a couple times with Emma," King says. "She asked questions. She's never played, but she's fantastic for never playing. Are you kidding? She's a quick study. Holy smokes."

The film also stars Steve Carell as Riggs. At the time of their match, Riggs was 55 and King was 29. Held in the Astrodome in Houston, the standard five-set match had a winning prize of $100,000, which King took home after a 6-4, 6-3, 6-3 victory.

In watching the film, King points to a particular moment she felt Stone nailed the role: The match's introductory press conference in New York.

"There's one part in the movie that, I've seen it, is really weird, because when she speaks, I thought I was speaking," King says. "That's how right on she is. OK. That's how scary.

"Her voice, her diction, her phrasing, if I closed my eyes, I thought I would be up there."

The film is set for a theatrical release on Sept. 22. Principal photography started back in April 2016. Andrea Riseborough, Sarah Silverman, Bill Pullman, Alan Cumming, Austin Stowell and Natalie Morales also have prominent roles in the film.

One more observation from King on Stone: "She started working out and building up muscle. She gained 15 pounds. She gained more definition."

King spoke about the film while at a press conference for the New York Empire. The New York-based Mylan World TeamTennis squad is moving locations from the West Side Tennis Club in Forest Hills to Court 17 at the USTA Billie Jean King National Tennis Center in Flushing Meadows. King was the commissioner of World TeamTennis from 1984-2001. (Her partner, Ilana Kloss, has been the commissioner since 2001). King sold her majority share of WTT this past March to Mark Elin and Fred Luddy, the owners of the Washington Kastles and San Diego Aviators.

The Empire start its second season this summer with marquee players John Isner, Eugenie Bouchard and Mardy Fish.

-- Follow Jeff Eisenband on Twitter @JeffEisenband. Like Jeff Eisenband on Facebook.

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