Top seed Elina Svitolina of Ukraine was forced to withdraw from the Alya Malaysian Open in Kuala Lumpur on Wednesday with a lower leg injury.
World number 10 Svitolina, who won back-to-back titles in Taiwan and Dubai, was the defending champion and had beaten South Korea's Jang Su-jeong 6-2 6-3 in the first round, when she received treatment between sets.
Japan's Nao Hibino was her opponent for the second round and won by walkover to advance to the quarter-finals.
Svitolina said on wtatennis.com: "I was looking forward to coming back to Kuala Lumpur to defend my title and I was excited to play here but, unfortunately, I have to withdraw because of a lower leg injury.
"I was struggling in my final match in Dubai and I was hoping to recover but even though I won today, I need to make sure I take care of my body for the rest of the season."
China's Zhang Kai-lin beat Risa Ozaki of Japan 6-2 6-4.
Lesley Kerkhove of Holland beat fellow qualifier Sabina Sharipova of Uzbekistan 6-4 6-4.
Source: PA
