Beijing - World number six Agnieszka Radwanska of Poland swept into the Tianjin Open quarter-finals on Thursday, dismissing the host country's Wang Qiang in straight sets.
The second seed prevailed 6-1, 6-1 in less than an hour.
But sixth seed Teliana Pereira of Brazil went out to unseeded Danka Kovinic of Montenegro, who won 6-2, 5-7, 6-1.
The $500 000 WTA tournament has seen a run of upsets, the most spectacular when Italian top seed Flavia Pennetta, who won the US Open last month, went out to a player ranked more than 400 places below her, Ukraine's Lyudmyla Kichenok.
Kichenok was eliminated herself on Thursday by Duan Ying-Ying of China, 6-7, 6-2, 6-4.