World number one Iga Swiatek continued her bid for a third straight Qatar Open title, while Japan's Naomi Osaka was knocked out in Doha.
Swiatek needed just 74 minutes to beat Belarusian former world number one Victoria Azarenka 6-4 6-0.
The Pole, who is on an 11-match winning run in Doha, will play an in-form Karolina Pliskova in the semi-finals.
Czech Pliskova ended Osaka's best run in nearly two years with a 7-6 (8-6) 7-6 (7-5) win.
Four-time major winner Osaka returned to tennis last month after giving birth to her daughter Shai in July.