Serena Williams had to use her Australian Open day off to deal with a 'crazy' crisis at her clothing brand

• Serena Williams used one of her recent days off at the Australian Open to deal with a "crazy" business crisis.
• Williams is the owner of her own fashion brand called "Serena."
• "Business keeps going," she said after beating Aryna Sabalenka in the fourth round on Sunday.

There's no rest for the wicked.

At least, that's the case for Serena Williams, who says she used one of her recent days off at the Australian Open to deal with a "crazy" business crisis.

The 39-year-old beat Aryna Sabalenka in the fourth round on Sunday, after which she detailed her how she had spent her rest day on Saturday doing anything but resting.

"It was so crazy," Williams said during her on-court interview after beating Sabalenka. "Yesterday on my day off, one of our people was out of the office. As CEO, I had to kind of step up a little bit."

Williams, who previously studied fashion at the Art Institute of Fort Lauderdale, is the owner of her own clothing brand called "Serena" which was launched in 2018.

"I was on the phone with our designer making final orders and deciding how much fabric we need for our new collection," she added.

"It was almost a mind trip because I was like, 'Oh my gosh! We have to play tomorrow but we've got to get this done.' Business keeps going."

Fortunately for Williams, the dilemma didn't prove too much of a distraction as she overcame Sabalenka in three sets, 6-4, 2-6, 6-4.

"I am happy to get through that one because it wasn't easy," the 23-time Grand Slam champion said after. "I felt like I was there, even the games I lost were super close and just one shot here or there."

Williams will now face second seed Simona Halep in the last eight on Tuesday.