Peng Shuai recorded her best win of 2019 as she defeated Kristyna Pliskova in three sets at the Jiangxi Open on Friday.
The former world number 14, who had not beaten a player ranked in the top 100 this year, saw off 81st-ranked Pliskova 6-3 0-6 6-4 after a gruelling one hour and 49 minutes in humid conditions.
Pliskova recovered from losing the first set to produce a dominant display in the second, reeling off 20 winners in six quick-fire games to seize the initiative in the contest.
However, Peng broke to move 5-4 ahead in the third and booked her place in the last eight with a forehand winner.
Peng will face compatriot Zhu Lin in the quarter-finals, the latter likely to be feeling the fresher of the two after top seed Zhang Shuai retired ill from their last-16 match at 6-0 1-0 down after only 39 minutes.
Fourth seed Elena Rybakina progressed with a 7-6 (7-4) 6-2 defeat of Xinyu Wang, while Nina Stojanovic beat former US Open champion Sam Stosur 6-4 6-3.
At the Hana-cupid Open, Alison van Uytvanck won a battle of the Belgians against Kirsten Flipkens to reach the quarter-finals.
Van Uytvanck led by a set and a break but eventually needed one hour and 55 minutes to take a 6-2 3-6 6-3 victory and secure a meeting with Mihaela Buzarnescu, who beat Kurumi Nara in straight sets.
Seventh seed Sara Sorribes Tormo made light work of Varvara Flink, winning 6-3 6-1, while Misaki Doi gave the home fans something to cheer with a 6-1 1-6 6-3 defeat of Australia's Zoe Hives.