It was the fifth straight time she has beaten Peng.
"I wouldn't say it was a straightforward match. It was a tough match. I played a cleaner match than I did yesterday,'' said Zvonareva. "But there is still room for me to improve in the next match because Shahar is a tougher player.''
Zvonareva, the world No. 5, will play 2006 champion Shahar Peer of Israel, who scored a 6-4, 4-6, 6-2 quarterfinal victory over Russia's Vera Dushevina.
Zvonareva said the seventh-seeded Peer has lots of experience and "is a fighter, patient and a good mover on the court.''
Earlier, Magdalena Rybarikova of Slovakia upset second-seeded Caroline Wozniacki of Denmark 6-4, 6-1 to earn a semifinal slot.
Rybarikova, ranked No. 51, capitalized on the weariness of the Danish teenager who was playing less than a day after her second-round win over Australian Open junior champion Ksenia Pervak of Russia.
"This is my best match for this year,'' the eight-seeded Rybarikova said. "I had to play aggressive and served well because she returns well.''
It will be the second semifinal of the year for 20-year-old Rybarikova, who made it to the last four at Hobart in the lead up to the Australian Open.
"It's been a good year for me. I have been working hard and beat some good players.''
Her semifinal opponent will be Sania Mirza of India, who beat Thailand's Tamarine Tanusugarn 7-5, 6-4 to make it to the final four.
Top seed Zvonareva pushes on to Pattaya semis
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