Tennis legends John McEnroe and Martina Navratilova joined forces to stage a protest calling for the Margaret Court arena in Australia to be renamed.
The pair unfurled a banner with their proposed new name of the second biggest tennis court at Melbourne Park, as the Australian Open heads into semi-finals.
Navratilova and McEnroe are two of Court's fiercest critics because of her views over the years on LGBT issues and apartheid.
Court, 77, holds the most major titles of any professional player, and won all four singles Slams in one year in 1970.
But she has been criticised for comments on South Africa's apartheid in 1970 including: "South Africans have this thing better organised than any other country, particularly America."
She also once called Navratilova a "great player" but said: "It's very sad for children to be exposed to homosexuality."
Melbourne Park's second biggest arena was renamed for Court in 2003, and even Billie Jean King, a pioneer for gay rights and social justice, has been supportive of it.
Navratilova and McEnroe have suggested the court be renamed the Evonne Goolagang Arena.
Goolagang is another Australian former number one player who is known as a trailblazer in indigenous Australian tennis, and Navratilova first pitched the name in an open letter to Court about three years ago.
Navratilova had been playing in a legends match on the 1573 court, next to the Court arena, when she climbed into the umpire's chair to address the remaining crowd.
Her microphone was turned off as she and McEnroe unfurled the protest banner.
Explaining the protest afterwards, Navratilova told the BBC she took action after what she saw was a lack of response from Tennis Australia.
She said: "I thought we got it going a couple of years ago. I thought Tennis Australia would do something - or the government of Victoria, as apparently they are the ones that make the decision - but nothing has happened.
"And Margaret keeps doubling down in basically attacking the gay and lesbian community. My wife Julia said, 'You're complaining about it, but what are you going to do?'
"And I'm like, 'I've done everything I can do. I've written a letter, I've been very vocal', and then when I landed here, and I came to the courts, I had this idea.
"I stopped in an art shop and got a canvas and some coloured pens and started colouring 'Evonne Goolagong Arena' on my hotel table in the Aboriginal version - a very amateur version of Aboriginal art - as an honour to Evonne Goolagong and where she came from.
"John, I ran into him, and on the spur of the moment I asked him because he also talked about renaming the arena. He's been very supportive of social change in tennis, so it was perfect.
"I wanted to be respectful, but most of all I just wanted to push the conversation forward again."
On Monday, Court was honoured in a ceremony marking the 50th anniversary of her Grand Slam. Tennis Australia specified it was honouring her sporting achievement and not espousing her views.
In a statement after the Navratilova and McEnroe protest, Australian Open organisers said in a statement: "We embrace diversity, inclusion and the right for people to have a view, as well as their right to voice that view.
"But the Australian Open has regulations and protocols with respect to how any fan, player or guest can use our facility, the event and the global stage it provides. This is to ensure the integrity of our event.
"Two high-profile guests have breached these protocols and we are working through this with them."
In a video released on Monday, McEnroe had pulled no punches when he talked about Court and what he called the ongoing problems with Tennis Australia.
He begged Serena Williams, who is chasing Court's record and sitting on 23 Grand Slam titles, to win two more "so we can leave Margaret Court and her offensive views in the past where she belongs".
Court, now a Pentecostal minister, has not issued any response.