Beijing - Former world No 1 Jelena Jankovic wilted in fierce heat in southeastern China, bowing out in the second round of the Jiangxi Open on Thursday in three gruelling sets.
The Serb sixth seed raced into a 6-2 first-set lead against home hope and qualifier Lu Jingjing before temperatures of 39 degrees Celsius (102F) on the Nanchang hard courts began to take their toll.
An ailing Jankovic, 32, called for a medical timeout in the second set as the match started to drift away from her.
Lu romped the set 6-1 to level the match and kept her cool to win the decider 6-2 and earn a place in the last eight.
In the quarter-finals, Lu will face Nao Hibino after the Japanese progressed when third seed Kristyna Pliskova, twin sister of current world No 1 Karolina, retired with a hand injury.
The WTA tournament is wide open following the exit on Wednesday of top seed Zhang Shuai of China.