Throughout her incredible tennis career, the Grand Slam record holder claimed to have encountered racial comments both on and off the court.

The World No. 1 champion wrote a moving essay for Fortune on Monday to honor Black Women’s Equal Pay Day, discussing the injustice she has experienced.

Champion: Serena Williams, pictured recently on her Instagram,  wrote of her experiences of inequality and racism in an essay published on Black Women’s Equal Pay Day

She wrote: ‘Growing up, I was told I couldn’t accomplish my dreams because I was a woman and, more so, because of the color of my skin. In every stage of my life, I’ve had to learn to stand up for myself and speak out.

‘I have been treated unfairly, I’ve been disrespected by my male colleagues and—in the most painful times—I’ve been the subject of racist remarks on and off the tennis court.’

She wrote that while she is ‘blessed’ with a drive and great support from family and friends, the remarks still hurt.

The Olympian continued, ‘The cycles of poverty, discrimination, and 𝓈ℯ𝓍ism are much, much harder to break than the record for Grand Slam titles.’

Never giving up:  Ms Williams, pictured here aged 16 in 1997, said she told to give up on her dreams of sports success because she is black

‘Black women are the cornerstone of our communities’: On Monday, she used her sporting prowess and celebrity status to promote Black Women’s Equal Pay Day

Work it! The Olympian penned a poignant essay about the gender wage gap on Fortune, writing ‘Together, we will change the story — but we are going to have to fight for every penny’

Stating her case: Earlier in the day the soon-to-be mom offered an abridged version of her essay in an Instagram caption, writing ‘Black Women’s Equal Pay Day… represents the number of days into 2017 a black woman must work to earn the same pay a white man made in 2016’

Earlier in the day the soon-to-be mom championed her cause on Instagram, offering a Cliff Notes version of her essay in the caption.

The world-renowned tennis champion struck a power pose while donning a gray tee with the words ‘phenomenal woman’ written across.

Her caption espoused a similar message as her essay, explaining ‘July 31 is Black Women’s Equal Pay Day, which represents the number of days into 2017 a black woman must work to earn the same pay a white man made in 2016.

‘That’s nearly 8 extra months!’ she continued.

Coming soon! The star is set to welcome her first child between August and September

New parents! Serena is set to welcome her first child with Reddit co-founder Alexis Ohanian, 34. The couple became engaged in December of last year. They are pictured in May in NY

The younger Williams sister went on, writing ‘Black women are the cornerstone of our communities, they are phenomenal, and they deserve equal pay.’

Though Serena was all about championing girl power, she’s keeping mum when it comes to the gender of her unborn child.

The star revealed on Instagram last week that she was going to let her 𝚋𝚊𝚋𝚢’s 𝓈ℯ𝓍 be revealed at birth.

‘So few surprises in life these days,’ she wrote ‘that’s why I’m waiting to find out the 𝓈ℯ𝓍 of the 𝚋𝚊𝚋𝚢.’

Serena is expecting her first child with Reddit co-founder Alexis Ohanian, 34.

The couple became engaged in December of last year, and are set to welcome their child between August and September.