World number one Maria Sharapova [Images] swept into the semi-finals of the China Open with a crushing 6-4, 6-1 victory over Japan's [Images] Shinobu Asagoe on Friday.

The Russian teenager came to the rescue of tournament organisers after Wimbledon [Images] champion Venus Williams [Images] pulled out with a knee injury before her quarter-final in Beijing [Images].

Had Sharapova lost, it would have left the $585,000 tournament shorn of its top four seeds before the semi-finals.

Second seed Lindsay Davenport [Images] withdrew with a back problem after winning in Bali at the weekend, while title holder Serena Williams [Images] suffered a shock defeat in her opening match.

Local interest also ended abruptly when Sun Tiantian and Peng Shuai bowed out earlier on Friday.

But Sharapova stayed on course for a fourth title of the year after victories in Tokyo, Doha and Birmingham with an easy win over the 39th-ranked Asagoe.

The 18-year-old clinched the first set on an Asagoe double-fault and quickly took a 5-0 lead in the second before closing out the match after 66 minutes.

Sharapova, who has won four of her 10 career titles in Asia, will face fellow Russian Maria Kirilenko in Saturday's semi-finals.

Kirilenko beat China's Olympic [Images] doubles champion Sun, conqueror of Serena Williams, 6-1, 6-3.

Chinese number one Peng fell to ninth seed Anna-Lena Groenefeld of Germany [Images] 7-5, 6-1.

Groenefeld will play Marta Domachowska in the semi-finals after the Pole's walkover victory against Venus Williams.

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