You can’t best the champ.

Simone Biles slammed conservative activist and former swimmer Riley Gaines on X, calling her a “straight up sore loser” after Gaines criticized trans athletes.

“You’re truly sick, all of this campaigning because you lost a race,” Biles wrote on Friday.

“You should be uplifting the trans community and perhaps finding a way to make sports inclusive OR creating a new avenue where trans feel safe in sports. Maybe a transgender category IN ALL sports!!,” she continued.

“But instead… You bully them… One thing’s for sure is no one in sports is safe with you around!!!!!” Biles, 28, closed, before tagging Gaines in a follow-up post, telling the ex-swimmer to “bully someone your own size, which would ironically be a male.”

The Olympic gold winner’s remarks come after Gaines commented on a post from the Minnesota State High School League, celebrating the school’s first ever Softball State Championship win.

“Comments off lol. To be expected when your star player is a boy,” Gaines, 25, wrote, making a reference to Marissa Rothenberger, a transgender pitcher on the team, per Fox News.

The activist didn’t take too kindly to Biles’ comments as she responded and expressed that she felt the gymnast’s take was “so disappointing.”

“It’s not my job or the job of any woman to figure out how to include men in our spaces. You can uplift men stealing championships in women’s sports with YOUR platform,” Gaines shot back on X.

“Men don’t belong in women’s sports and I say that with my full chest.”

Gaines continued, adding that her opinion on the issue is the “least controversial take on the planet.”

“Simone Biles being a male-apologist at the expense of young girls’ dreams? Didn’t have that on my bingo card. Maybe she could compete in pommel horse and rings in 2028,” she added.

“And the subtle hint at ‘body-shaming’ ???? Plzzzz I’m 5’5,” Gaines also said in response to the personal attack.