MELBOURNE (Reuters) - Australian tennis great Margaret Court has launched a tirade against transgender athletes and called the teaching of LGBTI materials at schools the work of the “devil” in a fiery sermon at her Perth church.

Court, a Christian pastor at the Victory Life Church she set up decades ago, made the incendiary comments just weeks before she is to be honored at the Australian Open on the 50th anniversary of her calendar Grand Slam.

In a video of her Sunday sermon posted online, Court said children as young as seven- and eight-years-old were deciding to change their sex.

“It’s so wrong at that age because a lot of things are planted in this thought realm at that age, and they start to question, ‘what am I?” she said.

“And you know with that LGBT, they’ll wish they never put the T on the end of it because, particularly in women’s sports, they’re going to have so many problems,” she said, referring to transgender people.

Court, who holds the record of 24 Grand Slam singles titles, said “the devil” wanted to control Australia so he could affect “people’s minds and mouths.”

“You know, even that LGBT in the schools, it’s the devil, it’s not of God,” the 77-year-old said.

Court’s comments come a month after Australia’s national tennis association issued a statement rebuking her views but also confirming her 1970 calendar Grand Slam would be recognized at the Jan. 20-Feb. 2 Australian Open.

Court has previously angered LGBTI activists and a number of tennis players, past and present, for expressing her opposition to gay marriage.

Last year, her great rival Billie Jean King added her voice to calls for a name change for the Margaret Court Arena show court at the Australian Open, saying she would boycott the venue if still a player.

Tennis Australia President Jayne Hrdlicka said last month that removing Court’s name from the stadium was not on the governing body’s agenda.