"Sakura could never lol," Osaka captioned the photo, making a reference to the fictional character from "Naruto," a Japanese manga series, who also has pink hair.
The 23-year-old athlete perfectly paired the look with matching graphic pink eyeliner.
Fans were stunned by Osaka's hot new hue and the post has received more than 432,000 likes.
She also received some encouraging comments from notables such as famous Jamaican sprinter Usain Bolt. "U wore it better," he said.
Another fan said of the look, "Oh my god you look lovely, I'm screaming in pink."
Osaka usually wears her natural curls, but there have been several other instances were she's switched it up. Last year, she shared photos wearing everything from long box braids to shoulder-length straight hair.
We also can't forget Osaka's statement-making look during the 2020 U.S. Open where she donned a face mask honoring Breonna Taylor, the 26-year-old Black woman who was shot and killed by Louisville police officers in March.