It didn't take long for Billie Jean King to become a puckhead. The tennis legend hadn't watched much hockey until this year, but she's found herself captivated by its rites and rituals.

"I love the way the home team will get in the circle and do the sticks," King said, describing the postgame stick salute players perform for fans. "That's really good. And the handshake line. They have a lot of great traditions that I love."

King and her wife, Ilana Kloss, came to Xcel Energy Center on Sunday to participate in customs old and new. As an adviser to the Professional Women's Hockey League, King kicked off Game 4 of the Walter Cup finals by leading the pregame "Let's Play Hockey" chant. She was ready to present the Cup to PWHL Minnesota if it had beaten Boston, but a 1-0 loss in double overtime put that on hold.

The Walter Cup will be hoisted by one of those teams Wednesday, after the deciding Game 5 at Tsongas Center in Lowell, Mass. That ritual will end the inaugural season of the PWHL, a league that has brought King's pioneering spirit to a new sport and a new generation of athletes.

At 80, the woman who beat Bobby Riggs in tennis' famous "Battle of the Sexes" is not done fighting. King is always looking for ways to push women's sports forward, and she saw a big opportunity when she was approached six years ago about starting a women's pro hockey league. Sunday, she reflected on its first season like a proud godmother — and an enthusiastic new hockey fan.

"When [investor] Mark [Walter] told us yes, it was a huge day," King said. "We knew then it had a chance to not only survive, but to really make it in a big way.

"I think it's unbelievable. It's way beyond my expectations."

Though King knew nothing about hockey in 2018, she was intrigued when Kendall Coyne Schofield — a U.S. Olympian who now plays for PWHL Minnesota — made the pitch for a new league. King took it to her friends Mark and Kimbra Walter.

Mark Walter, a financier and owner of teams including the Los Angeles Dodgers, didn't immediately accept. But King believed in the idea, and she persisted.

"It took us a few years," King recalled. "When [Walter] says yes, he means it, and he means long term."

In the PWHL, King sees an echo of women's tennis 50 years ago. Back then, she helped organize the world's best players to set their sport on a path to equality. The world's best hockey players are doing the same with their new league, working in concert to build something that will pay the biggest dividends to future generations.

King is thrilled by fans' embrace of the PWHL, lauding Minnesotans for showing up and buying all the available merchandise. She said all six host cities have been "unbelievable," and she has met many parents who are grateful their daughters can chase a dream of playing pro hockey.

For King, that's the point. She plans to keep working toward a world where girls' aspirations are not limited.

That means pushing to get more media rights money for women's sports. More media coverage than the 14% of total sports coverage currently allotted to women. More investment from companies that spend far more on men's sports than women's.

King would even like to see new hockey traditions made in the PWHL. That takes time, but she's committed to the long haul.

"The novelty will be over after the first year," she said. "And then, you've got to work even harder."