Beijing - Top seeds Victoria Azarenka and Maria Sharapova steamrollered their opponents on Friday, cruising into the semi-finals of the Beijing Open with the loss of just two games between them.
Showing ominous form, French Open champion Sharapova, yet to drop a set in China, won the first set 6-0, and was 3-0 up in the second when Germany's Angelique Kerber quit the match citing an injury to her right foot.
The Russian stayed on track for a re-match of this year's Australian Open final, which she lost to Azarenka, who has also yet to drop a set this week. Azarenka also came out on top in their semi-final clash at the US Open.
"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," Sharapova said.
"She had a few break points and long games on her serve," the Russian added, saying Kerber was probably lacking fitness at the end of a long season.
"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," Sharapova said.
"The schedule takes its toll on everyone. It's a normal process. If you feel like it's too bad, you've got to take care of it."
Azarenka, from Belarus, maintained her scintillating form, dismissing Romina Oprandi 6-2, 6-0.
"It's never easy to go in the tennis court and win the match even though the score was like this," Azarenka, 23, said.
"It's important to stay tough and have that concentration to make sure that you can win every ball and every point. I felt like I was playing well, but it wasn't easy," she added.
In the men's draw Chinese wildcard Zhang Ze's fairytale run came to an end when he suffered a straight-sets defeat to Germany's Florian Mayer in the quarter-finals.
The 22-year-old, ranked 165th in the world, made history in the last 16 when he became the first Chinese man ever to beat a top 20 player, dumping out France's Richard Gasquet.
His defeat of the Frenchman, ranked 14th, also meant Zhang was the first men's player from China to reach the quarter-final of an ATP event since Pan Bing made the semi-finals in Seoul in 1995.
But matching Pan's 17-year-old mark proved a step too far for the right-hander from Nanjing, with world No 29 Mayer winning 6-3, 6-4.
Third seed Jo-Wilfried Tsonga of France defeated Russia's Mikhail Youzhny 6-3, 6-2 to reach the semi-finals.
Results from the China Open in Beijing on Friday (x denotes seeding):
Victoria Azarenka (BLR x1) bt Romina Oprandi (SUI) 6-2, 6-0
Maria Sharapova (RUS x2) bt Angelique Kerber (GER x5) 6-0, 3-0 (retired)
Li Na (CHN x7) bt Agnieszka Radwanska (POL x3) 6-4, 6-2
Florian Mayer (GER) bt Zhang Ze (CHN) 6-3, 6-4
Jo-Wilfried Tsonga (FRA x3) bt Mikhail Youzhny (RUS) 6-3, 6-2