Top seeds Angelique Kerber of Germany and Elina Svitolina of Ukraine secured their tickets in the quarter-finals at WTA Dubai Open Wednesday, while Chinese Wang Qiang stunned French top player Kristina Mladenovic.
The WTA world number two and the tournament's top seed Kerber was hardly challenged in the round of 16 when she beat Monica Puig of Puerto Rico by 6-2, 6-3.
The best German female player since Grand Slam legend Steffi Graf will play on Thursday in the quarter finals against Ana Konjuh of Croatia.
Wang Qiang upset Mladenovic by 6-1, 6-4 in one hour and 21 minutes.
"I played well and I played more on her forehand, according to the advice from my coach," said 25-year-old from Tianjin.
Wang, ranked 76th in the world, will encounter Latvian Anastasija Sevastova who defeated Wang's countrywoman Shuai Peng 6-4, 6-3.
American hopeful Lauren Davis will play against Svitolina who beat Serena Williams last year at the Summer Olympics in Rio.
Earlier in the day, Svitolina needed three sets to defeat American Christina McHale 4-6, 6-4, 6-3.
Svitolina complained about pain in her toes after the match, "I ran so much and I hope to recover until the quarter finals on Thursday."
The fourth final on the round of eight will be decided between Catherine Bellis of the United States and Caroline Wozniacki of Denmark.
The final of the 2.6 million dollar tournament will take place on Saturday.