Wimbledon champion Simona Halep has retired from the Wuhan Open after suffering a lower back injury.
Despite the intervention of a physiotherapist, she was forced to withdraw when trailing 5-4 in the first set against the Kazakh wildcard.
Meanwhile, Ashleigh Barty defeated Sofia Kenin 6-3, 7-5 to secure a place in the quarterfinals.
Third seed Elina Svitolina also progressed against Svetlana Kuznetsova.