One of the hardest things about being a rising tennis champion, says Serena Williams, was having to compete with her big sister.

Serena Williams released a new docu-series earlier this month. In The Arena: Serena Williams can be seen on ESPN. (PHOTO: Gallo Images/Getty Images)

Serena (42) addresses her relationship with Venus (43) in her new documentary series In The Arena: Serena Williams, which recently premiered at the Tribeca Film Festival in New York.

“I didn’t like to compete with my best friend. It’s very difficult,” Serena said, referring to her sister.

“Some people are like, ‘I want my sibling to go down.’ And I’m like, ‘I want her to win too,’ and so it was very difficult. It was very hard.”

Serena and Venus Williams played against each other on many occasions at various tournaments, something Serena says she struggled with emotionally. (PHOTO: Gallo Images/Getty Images)

In the eight-part documentary, which will air on ESPN in the US, Serena says that in the early part of her career she felt overshadowed by her sister.

“I actually never thought I was good at tennis. You have to understand, I was growing up next to Venus Williams. I could never beat Venus unless I cheated.”

The series delves into the psychological impact of their rivalry, with Serena saying she felt guilty when she beat her sister, and often cried after their matches.

“I hated playing Venus. It was torture.”

The tennis legend has embraced her business interests and motherhood since retiring from the game in 2022.

She and her husband, Alexis Ohanian, have two daughters, Adira, born in August 2023, and Olympia (6).

Asked at the premiere of the doccie if she would consider playing against young tennis star Coco Gauff (20), Serena replied, “Let me ask my knees.”

The docu-series will be different from the King Richard biopic, which was released in 2021 and starred Will Smith as the Williams sister’s father, Richard.

While the movie focused on the girls’ early years, the series promises a more comprehensive look at Serena’s life, featuring interviews with family and friends.

At a post-premiere discussion panel at Tribeca, Serena said future episodes will include appearances from family members, discussions about topics like racism and mental health, as well the period leading to her retirement.