Top seed Elina Svitolina overcame Lucie Hradecka to reach the quarter-finals of the Taiwan Open and Sam Stosur fought back from a set down to move into the last eight on Thursday.
Svitolina, eyeing a fifth WTA singles title, lost just three games in a first-round thrashing of Evgeniya Rodina in Taipei City, but did not have things all her own way against Hradecka.
The Czech qualifier fashioned 12 break points, of which she was only able to win one as world number 13 Svitolina prevailed 6-4 7-5.
Hradecka saved four match points before Svitolina came up with the only break of the second set to ensure she will face outsider Ons Jabeur in the quarter-finals.
Second seed Stosur dug herself out of a hole to avoid an upset, beating qualifier Dalila Jakupovic 3-6 7-5 6-3.
Stosur, 133 places above her Slovenian opponent in the rankings, was broken six times but won four games in a row in the deciding set to set up a clash with Peng Shuai.
Fifth seed Katerina Siniakova won a maiden WTA singles title at the Shenzhen Open last month, but there be no repeat this week after the Czech went down 6-1 6-3 to Peng..
Zhu Lin won the final second-round match of the day, battling back to see off Kurumi Nara 4-6 6-1 6-2.