TIANJIN—Maria Sharapova surged into the Tianjin Open quarter-finals on Thursday as she pursues her first tournament victory since her return from a doping ban.
The Russian former world number one defeated Magda Linette of Poland 7-5, 6-3 and will next play either Swiss qualifier Stefanie Voegele or fifth seed Yulia Putintseva of Kazakhstan.
The 30-year-old Sharapova has been on the comeback trail since April after serving a 15-month suspension for taking the banned substance meldonium.
Sharapova, a five-time major-winner, is now ranked a lowly 86 in the world and she needed a wildcard to enter the Tianjin tournament.
She saw off 71st-ranked Linette in just over 98 minutes to reach only her second quarter-final since her return to action.
Meanwhile, Juan Martin del Potro fought back from a set down to beat racquet-smashing rising star Alexander Zverev and reach the Shanghai Masters quarter-finals on Thursday.
The seasoned Argentine recovered to win 3-6, 7-6 (7/5), 6-4 in one hour, 55 minutes against the 20-year-old Zverev and will next play either Viktor Troicki or John Isner.
Zverev was going after his sixth title of an outstanding season and was comfortable in the first set against del Potro, the 2009 US Open champion.
The German prodigy and the 29-year-old, whose career has been beset by injury, went toe to toe in the second set and the tie break was just as tight until del Potro grabbed the crucial mini-break.
And then came the turning point — and the flash of anger from third seed Zverev — as he yielded the crucial service break to go 3-2 down in the third set.