Maria Sharapova had 11 aces and saved seven of 10 break points to beat Alison Riske 4-6, 6-3, 6-2 on Tuesday and advance to the Shenzhen Open quarterfinals. The five-time major winner will next face Zarina Diyas, who upset third-seeded Zhang Shuai 6-3, 6-7 (5), 6-4.
"Although I would've wanted a quick and easy victory, these are the kind of matches that you need, especially with such a short preparation going into the Australian Open," Sharapova said.
Earlier, Kristyna Pliskova, the twin of former No.1-ranked Karolina Pliskova, beat French Open champion Jelena Ostapenko 6-1, 6-4.
Ostapenko, who beat Serena Williams in an exhibition match in Abu Dhabi on Saturday, was overwhelmed by Pliskova's powerful serves.
"I felt a bit nervous in the second set, but my serve was really working today, which was a big help," Pliskova said.
Pliskova will next play Ana Bogdan, who beat Camila Giorgi 6-4, 6-2.
Aryna Sabalenka also advanced to the quarterfinals with a 6-1, 6-0 victory over Danka Kovinic, while Timea Babos defeated Magda Linette 6-2, 6-1.
