Madonna on Tuesday hit back at claims that she was drunk on stage in Australia last week, saying she was merely playing a character during a performance in which she dressed as a clown and fell off a tricycle.
On Instagram, Madonna, 57, thanked fans for supporting her after media reports and video clips showed her behaving erratically at shows in Melbourne last Thursday and Friday.
She is in the midst of a custody battle with ex-husband, film director Guy Ritchie, over their 15-year-old son, Rocco.
"Too bad people don't know the art of acting and playing a character. I could never do any of my shows high or drunk," Madonna wrote.
"Underlying all of this is sexism and misogyny which proves that not only do we not get equal pay, but we are also still treated like heretics if we step out of line and think outside the box."
She had donned a wig, top hat and striped stockings to perform a special Tears Of A Clown show in Melbourne, outside of her current Rebel Heart world tour.
She later posted a photo of herself drinking what her representatives said was one Cosmopolitan cocktail - usually made with vodka and cranberry juice - on stage.
Video clips posted by audience members showed her at times to be stumbling and speaking erratically during the show - a contrast to her usual highly choreographed tours. In the show, she showed a large photo of Rocco as a young boy, telling the audience "I probably would have enjoyed myself a bit more on this tour if he hadn't disappeared so suddenly".
Rocco has been living with his father in London since December after refusing to return to his mother's New York home.