US tennis legend Billie Jean King waves during a 100 years of Centre Court celebration on day seven of the Wimbledon tennis championships in London, July 3, 2022. (PHOTO /AP)

NEW YORK - Retired tennis great Billie Jean King believes women's sports are at another "tipping point," as the US Open celebrates 50 years of equal prize money with the Grand Slam's grand dame taking center stage in New York.

The American trailblazer was a driving force behind the tournament's move to equalize prize money for men's and women's competitors. When she won her third US Open title in 1972 she earned $10,000, compared with $25,000 for the men's winner.

When she won her third US Open title in 1972 she earned $10,000, compared with $25,000 for the men's winner

"I'm thinking, 'God, I only got 10 and he got, you know, (Ilie Nastase) got 15'," she told reporters on Thursday, recalling a news conference she participated in at the time. "So I said to everyone and I was just feeling this... I said, 'This really stinks. I don't think the girls will be back'."

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She says now that she had not spoken with her cohorts before drawing that line in the sand - though it scarcely mattered. The next year the US Open became the first sporting event to offer equal prize money to men and women.

Billie Jean King holds up trophy she received in the Forest Hills neighborhood of the borough of Queens in New York, Sept 9, 1972, for winning the women's title of the US Open tennis tournament. King had just won the 1972 US Open singles title when she demanded that the women's champion be paid the same as the men's winner the next year. That led the US Open to become in 1973 the first sporting event to offer equal pay, and the 50th anniversary of that is being celebrated at this year's event. (PHOTO / AP)

The Australian Open took another 28 years to do the same. Roland Garros equalized prize money across the board in 2007, after offering equal paydays to champions only in 2006, and Wimbledon evened up their men's and women's purses in 2007.

We're at the tipping point where people think there's money in women now, 

Billie Jean King 

Already a reliable fixture at the year's final major, King's face will be near-ubiquitous when fans arrive for the start of the main draw on Monday, as organizers named the anniversary as the "central theme" for the tournament.

Artwork celebrating the milestone adorned buildings and saturated the offerings at a gift shop in the tennis center named for King on Thursday.

"I don't ever usually look at myself," King said. "But this one, I may have to."

The celebration coincides with the 50th anniversary of the WTA - which King spearheaded - and what she calls another pivotal moment for women's sport.

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"We're at the tipping point where people think there's money in women now," said King, who in 2020 joined the investment group for the National Women's Soccer League (NWSL) team Angel City FC. "That's why they're buying soccer teams. That's why they're buying the basketball teams. That's why they really are investing now. There's no question."

US former tennis player Billie Jean King (center) poses with Spain's players celebrating with the trophy after winning the Australia and New Zealand 2023 Women's World Cup final football match between Spain and England at Stadium Australia in Sydney on August 20, 2023. (PHOTO / AFP)

King traveled to Australia to watch the Women's World Cup, which wrapped up this month and pointed to the record television audiences for the expanded tournament as evidence of progress.

"That's why people will start investing when they get those kinds of reports," King said. "The more investment we get, the more chance we have to win."

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The 79-year-old confessed that she had only recently returned to her first love, picking up the racquet again during the pandemic after a two-decade-long hiatus at the encouragement of her wife, Ilana Kloss.

"I'm really crazier than ever because I can feel the ball against the strings," she said. "I've got horrible knees... I mean, I'm a mess, but (to) get out there and hit is great."