DOHA, Qatar -- Top seed Kerber was ousted in her first match by 19-year-old Daria Kasatkina, who claimed the three-set victory. With the 6-4, 0-6, 6-4 win over the former No. 1, the Russian advanced to the quarterfinals where she will face 2016 Olympic gold winner Monica Puig.
"I am happy that I went through this and I am in the quarters," said Kasatkina in her post-match interview.
The world No. 2 wasn't feeling one hundred percent.
"I was not feeling the best today - I'm trying to find my rhythm," the 29-year-old said in her post-match press conference.
In other matches, Caroline Wozniacki defeated Agnieszka Radwanska in straight sets 7-5, 6-3. The former world No. 1 will next face American Lauren Davis, who defeated Elena Vesnina in a tight three-setter 5-7, 6-3, 7-6(7). Davis won her maiden WTA trophy at the ASB Classic in January.
Dominika Cibulkova advanced to the semifinals with a 6-3, 3-6, 6-4 win over Samantha Stosur. She awaits the winner of Karolina Pliskova and Zhang Shuai.