World number four Ana Ivanovic eased past French teenager Alize Cornet 6-1 7-6 to reach the China Open quarter-finals on Thursday, while China's Zheng Jie delighted home fans by thrashing Japan's [Images] Ai Sugiyama.

The 20-year-old Serb needed only 30 minutes to close out the first set against Cornet and broke early in the second to race to a 3-1 lead.

The 18-year-old Frenchwoman broke Ivanovic's serve twice to fight her way back into the match but ultimately wilted under pressure when serving for the set at 6-5.

Ivanovic attacked Cornet's serve furiously to break back and then steam-rolled the world number 19 in the tie-break 7-1.

She faces a quarter-final meeting with Zheng, who knocked her out of Wimbledon [Images] this year on the way to becoming the first Chinese to make a grand slam singles semi-final.

"I think I can play better this time," Ivanovic told reporters.

"I didn't prepare in particular for (Zheng) but I think it should be a tough match."

Zheng trounced Sugiyama 6-1 6-2 to the delight of the small but vocal home crowd, a match she had brooded on for four years after being beaten by the Japanese 33-year-old at the Athens Olympic [Images] Games.

"It was a shame to lose at Athens ... I said to myself I'm definitely going to beat her next time," said 25-year-old Zheng.

Russia's [Images] Vera Zvonareva [Images] advanced to a quarter-final against Anabel Medina Garrigues of Spain after beating Francesca Schiavone of Italy [Images] 7-6 6-2.

Slovak Dominika Cibulkova, who upset eighth seed Anna Chakvetadze [Images] 6-3 6-2 on Thursday, will face fourth seed Svetlana Kuznetsova [Images] of Russia in the last eight.

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