Serena Williams’ struggle in the China Open round of 16 (PHOTOS)

BEIJING, China — World No. 1 female tennis player Serena Williams overcame tough challenges from Russian star Maria Kirilenko to enter the quarterfinals of the China Open here on Thursday.

Williams won her 70th match of the year and also improved her record to 8-0 against Kirilenko. The Russian made the top-ranked Williams work hard for the win, though.

The American fought off three set points and rallied to beat Kirilenko 7-5, 7-5. The unseeded Russian broke Williams to take a 5-4 lead in the first set, then held three set points on her serve before Williams recovered. Kirilenko also broke Williams in the second set and took a 4-2 lead before faltering down the stretch.

The author is the editor-in-chief of business channel and sports columnist with the People's Daily Online.