Victoria Azarenka and Maria Sharapova encountered few problems en route to booking their spots in the semi-finals of the WTA Tour event in Beijing.
The No 1 seeded Azarenka crusied past Romina Oprandi of Switzerland in just 56 minutes, winning 6-2 6-0.
The 23-year-old from Belarus conceded just four points in the second set and in five matches this week has lost only 15 games in total.
Sharapova, meanwhile, did not lose a single game against Angelique Kerber of Germany who retired with a foot injury in the second set.
The No.5 seed Kerber lost the first nine games before deciding to call it a day.
Sharapova said: "I thought we played a high level of tennis in the first set and a half, and even though the scoreline was 6-0 3-0 there were many games that went to deuce.
"She had a few break points and long games on her serve. I actually didn't see much of her injury. I was surprised she called the trainer and even more so when she retired quickly after that."
Although the top two seeds progressed with ease, the No.3 Agnieszka Radwanska was beaten by local favourite Li Na in straight sets - 6-4 6-2.
Li will face Sharapova for a place in the final while Marion Bartoli stands in Azarenka's way after she overcame a mid-match wobble to defeat Carla Suarez Navarro of Spain 6-0 2-6 6-4.