WATCH: Osaka shares nighttime routine with Harper Bazaar

How does a two-time Grand Slam champion get ready for bed? Naomi Osaka recently gave a glimpse of her nightly routine to her fans in Harper Bazaar's "Go to bed with me" series.

"I really hope beauty people don't see this, because I know they are going to look at me taking off my makeup and be like what the heck," Osaka said.

Osaka has picked up two Grand Slams and been ranked No. 1 in the world, but when it comes to makeup and skin care regimes, she isn't an expert and sticks to the basics.

"Falling asleep with makeup on is a big no from me," Osaka said, as she wiped her makeup off.

Osaka's mother scared the world No. 10 by telling her that if she falls asleep with makeup on, she will get a lot of acne. "To be honest, I take makeup off so badly, I think in the end, I do sleep with a little bit of makeup on," Osaka said.

The next part of Osaka's six-step process includes washing her face with a gel cleanser scented with coconut and prickly pear. Osaka said she likes sticking to what she's used to since she has sensitive skin.

"Two moisturizers are better than one," said Osaka, after using a light moisturizer followed by a sleeping gel cream. The 22-year-old quickly moved on to adding a lip balm and finished her routine off with a cooling stick for under her eyes to avoid puffiness in the morning.

Simple and sweet is the perfect way to describe Osaka's nightly beauty routine. Even though she might not be an expert, one would never know.