NANCHANG, China - Lu Jing-Jing reached the quarterfinals of the Jiangxi Open for the first time after coming from a set down to beat Jelena Jankovic 2-6, 6-1, 6-2 on Thursday.

The Serb appeared to have problems coping with the heat after taking the first set as Lu grew in confidence.

With temperatures reaching 39C at the start of the match, it was former World No 1 Jankovic who made early light of the conditions in the first set, storming past the home favorite.

After serving first, qualifier Lu was broken in the opening game and went on to also lose her next two service games, to trail 4-1. She finally held to reach 5-2 but Jankovic, with 15 WTA singles titles to her name, took her second set-point to move ahead in just 37 minutes.

An early break in the second set gave Lu a 3-0 lead as sixth seed Jankovic began to struggle with the conditions. Kristyna Pliskova had an issue with the heat the previous day and Jankovic called for a trainer to advise her at the changeover.

A medical timeout was called before play resumed after a delay of just under 10 minutes. Lu took immediate advantage, taking a second break-point to lead 4-0 before saving a break on her own serve to move 5-0 ahead. Jankovic finally registered but the Chinese player claimed the set 6-1 to level the match.

Lu Jing-Jing reached the last eight in Nanchang (Jiangxi Open)

Jankovic was broken early in the deciding set before the Serb found some resolve in the fifth game, saving five break points - including a point penalty after being warned for taking too long between serves - before taking the game to pull back to 3-2. However, Lu broke again before serving out the match to take her place in the last eight.

"I was feeling really weak," Jankovic said afterwards. "I was continuing to play, because I don’t like to give up. I just didn’t have any power. I was trying my best, [but] I just physically couldn’t find the energy or the power to go till the end. My opponent was much fitter, much stronger and she could do it." 

Lu will face Nao Hibino in the quarterfinals, the Japanese progressing after third seed Pliskova retired hurt with a hand injury, when leading 3-0 in the first set. With the top seed, Zhang Shuai, having been beaten on Wednesday, the tournament remains wide open.

Elsewhere on the fourth day, wildcard Wang Yafan powered past Chang Kai-Chen 6-0, 6-2, despite being ranked 34 places below her opponent from Chinese Taipei. Zhu Lin beat compatriot Xun Fangying 6-3, 6-4 and will play Peng Shuai in the quarterfinal. The second seed progressed after Tereza Martincova retired hurt when trailing 6-2, 3-2.