Maria Sharapova eased into the last 16 of the China Open with a straight sets victory in Beijing over Sorana Cirstea.
The 25-year-old second seed beat the world number 29 6-2 6-2 to set up a meeting with Slovenia's Polona Hercog.
Defending champion Agnieszka Radwanska took more than two hours to overcome Spanish qualifier Lourdes Dominguez Lino of Spain 2-6 6-1 6-4.
In the men's draw, world number two Novak Djokovic beat Carlos Berlocq 6-1 6-3 to reach the quarter-finals.
The Serb, broken twice in the second set, will play Jurgen Melzer on Friday after the Austrian defeated Alexandr Dolgopolov 7-6 (9-7) 2-6 6-1.
His compatriot Jelena Jankovic was knocked out though, losing to Spain's Carla Suarez Navarro 7-5 6-4.
Meanwhile, China's Li Na reached the last 16 by defeating Nadia Petrova of Russia 6-1 6-2 in front of a capacity crowd.
And Switzerland's Romina Oprandi beat former world number one Ana Ivanovic 6-4 6-3 to reach the last eight.