World no 1 Naomi Osaka defeated Hsieh Su-wei 6-4, 6-3 in her first clay court match of the season in Stuttgart on Thursday.
US and Australian Open champion Osaka, who lost to Taiwanese veteran Hsieh in Miami last month, secured a place in the quarter-finals against Croatia’s Donna Vekic.
Osaka, 21, broke Hsieh three times in total to beat Hsieh for the second time in three attempts this year, having also defeated her on the way to lifting the title in Melbourne.
Osaka is less than 200 points ahead of Simona Halep in the WTA rankings, although the Romanian pulled out of this week’s tournament with a hip injury.
