Billie Jean King spent part of her 80th birthday doing what she loves most — playing tennis. 

The 12-time grand slam champion posted a video to X captioned “Tennis on my 80th,” taking some impressive forehand and backhand shots on Wednesday.

She followed that with a picture of her holding up a cake, baked by her niece, with her signature BJK initials on it.  

“Couldn’t ask for more. I am so lucky,” King wrote. “80, I’m ready for you.”

The former No. 1 player in the world further reflected on the day in another post and thanked the WTA for their special tribute video. 

“Today, I am 80 years young,” King wrote. “Relationships are everything. I am fortunate to have been surrounded by loved ones all my life. I look forward to each day. Having [my wife] Ilana by my side is my best gift. Creating opportunities for others makes me so happy. 

“And I’m not done yet!”

King, who also won 16 Grand Slam doubles titles and 11 mixed doubles crowns, is an American sports icon who has fought for equality and empowerment throughout her career.

The U.S. Tennis Center in Flushing Meadows is dedicated to her.

King remains an ambassador for women’s sport and will forever be known for defeating Bobby Riggs in the “Battle of the Sexes,” 6-4, 6-3, 6-3 in 1973 in a match that was watched by 90 million people worldwide.