Wimbledon champion Angelique Kerber suffered a shock last-16 exit from the Dubai Championships after being beaten by unseeded Hsieh Su-wei 5-7 6-4 6-0 on Wednesday.
Taiwan’s Hsieh was two games away from defeat when Kerber rallied from 2-4 down to draw level at 4-4 in the second set, but the world No.31 won eight of the last 10 points to send the match to a decider.
The 33-year-old Hsieh ultimately scorched into the last eight, converting three break points to bagel her German opponent.
Hsieh, who recorded her first win in three attempts against Kerber, will next face Karolina Pliskova for a place in her second semi-final of the season, and first since the opening week of 2019 at the Auckland Classic.
Australian Open runner-up Petra Kvitova overcame American qualifier Jennifer Brady 7-5 1-6 6-3 to reach the last eight for the first time in six years.
World No.4 Kvitova was two points away from losing the opening set in the ninth game when she responded in style by clinching 14 of the next 16 points.
Kvitova benefited from Brady’s sixth double fault of the match to secure a break in the first game before producing a string of delightful serve and volley combinations to extend her lead.
While Kvitova squandered her first match point by producing a 10th double fault, the Czech sealed a victory with a clinical point finished at the net.
“The wind was just terrible today, to be honest,” said Kvitova.
“I couldn’t really serve well today at all. It’s been big struggle for me.”
Third-seeded Simona Halep joined Kvitova in the quarter-finals after the Romanian continued her steady progress with a 6-3 7-5 win over Ukraine’s Lesia Tsurenko.
Two-time defending champion Elina Svitolina extended her winning streak in Dubai to 11 matches after defeating two-time grand slam champion Garbine Muguruza 6-1 6-2.