Maria Sakkari took out twenty-three-time major champion Serena Williams to punch her ticket into the quarterfinals.

Day four of the Western and Southern Open, Maria Sakkari took out twenty-three-time major champion Serena Williams to punch her ticket into the quarterfinals.

Tennis Channel Report:

Day four of the Western and Southern Open, Maria Sakkari took out twenty-three-time major champion Serena Williams to punch her ticket into the quarterfinals. The number 13 seed fought back from a set down before closing out one of the biggest wins of her career. She'll face Britain's Johanna Konta for a spot in the final four.