Maria Sharapova has reached the quarter-finals of the Tianjin Open with a 7-5 6-3 defeat of Poland's Magda Linette.
Thursday's victory marks the third last-eight showing of the season for the five-time grand-slam winner from Russia, fighting to revive her ranking after serving a 15-month suspension for using an illegal doctor-prescribed medication.
Former No.1 Sharapova saved nine of the 10 break points she faced against the 71st-ranked Linette.
The Russian won the opening set after a brief struggle, suffering her only break of serve in the second game of the second set. But she returned the favour twice to seize the momentum and came through in just over 90 minutes on her fourth match point.
The 30-year-old Russian next plays Stefanie Voegele. The Swiss defeated fifth seed Yulia Putintseva of Kazakhstan 6-2 6-3.
Third-seeded Peng Shuai of China also advanced to the quarter-finals, beating countrywoman Wang Xiyu 6-2 6-2.
Italian Sara Errani downed Beatriz Haddad Maia of Brazil 6-4 4-6 6-3, while American Christina McHale accounted for Maria Sakkari of Greece 6-0 6-4.
