Elina Svitolina caused an upset at the China Open on Thursday as she sent world number one Angelique Kerber crashing out in the third round.
A quarter-final berth continues to elude world number one Angelique Kerber after she was beaten in straight sets by Elina Svitolina at the China Open.
Since usurping Serena Williams at the top of the world rankings by winning the US Open, Kerber has fallen at the last 16 in successive tournaments with the latest setback coming courtesy of a 6-3 7-5 defeat to Svitolina on Thursday.
Svitolina will meet Daria Gavrilova in the quarter-finals after the Australian beat Caroline Garcia 6-4 6-3.
Agnieszka Radwanska overcame a familiar foe as she beat Caroline Wozniacki 6-3 6-1, while Johanna Konta booked herself a last-eight spot with a fine three-set victory over fifth seed Karolina Pliskova.
Things were not so positive for Simona Halep, though. The fourth seed was unable to avenge her Australian Open defeat to Zhang Shuai as the Chinese player recorded her second win of the year over the 25-year-old.
An out-of-sorts Halep was convincingly beaten 6-0 6-3 under the roof, but Alize Cornet and Yaroslava Shvedova will have to return on Friday after rain denied them the chance to play their third-round tie.
TOUGH AT THE TOP FOR KERBER
Reaching world number one was a crowning moment of Kerber's career, but since her win at Flushing Meadows she has struggled to make it to the latter stages of tournaments.
Her defeat to Svitolina was the latest example. Kerber - who has played 35 matches since July - battled to save a couple of match points before 16th seed Svitolina wrapped things up.
It is the second time this year the Ukrainian has beaten the world's top-ranked player following her victory over Serena Williams at the Rio Olympics.
"I was just trying to be really focused on every ball, and of course try to win," said the 22-year-old.
"I was trying to think about my next step, what I should try to do. I tried to make my first serve and concentrated on the next shot, but still I was a little bit shaky!"
RADWANSKA OUSTS WOZNIACKI AGAIN
Wozniacki and Radwanska had shared a win apiece at their past two tournaments, but it was the latter who triumphed in their latest encounter thanks to a 6-3 6-1 win.
Radwanska is now the only defending champion left in the field, the third seed having claimed the title in 2011.
"I don't think it has happened to me ever to play someone three weeks in a row," Radwanska told a media conference after her win. "It's good that we're playing different tournaments next week so we cannot play each other again!"
KONTA'S FINALS CHARGE CONTINUES
After her breakout season in 2015, Konta has continued to go from strength-to-strength this year and a place in the WTA Finals remains a possibility.
Thursday's 6-1 3-6 7-6 (7-2) win over Pliskova ensures her charge for a spot in Singapore remains on course.
Should Konta go all the way to the final - and other results go her way - the Briton will move into a qualification spot for the season-ending tournament.