Wuhan, September 30

Britain’s Johanna Konta pulled off a stunning third-set revival today as she floored top seed Simona Halep in the biggest upset yet at the shock-prone Wuhan Open.

As defending champion Petra Kvitova joined the exodus of top seeds, world No 2 Halep appeared to have the measure of 66th-ranked Konta when she led 5-1 in the third. But 21-year-old Konta, who reached the US Open last 16 as a qualifier, bravely fought her way back to take it 6-3, 3-6, 7-5 and set up a quarter-final with American great Venus Williams.

It was the most remarkable result so far of what has been a highly unpredictable tournament in central China after a rash of upsets and retirements. Last year’s winner Kvitova had looked exhausted after Tuesday’s three-set tussle with Daria Gavrilova, and it was no surprise when she went down to US Open finalist Roberta Vinci.

The Czech led 4-0 in the first set but she lost the opener in a tie-break and then struggled in the second as Italy’s Vinci took it 7-6 (7/3), 6-2. “I think she’s playing with a lot of confidence right now,” Kvitova said of Vinci, who ended Serena Williams’ bid for a calendar-year Grand Slam to reach the US Open final.

With Maria Sharapova, Victoria Azarenka, Caroline Wozniacki, Belinda Bencic also departing early, Ana Ivanovic became another big name to fall when she lost Garbine Muguruza.

The Serbian former world No 1 won the first set but it was one-way traffic thereafter as Muguruza suddenly rediscovered her mojo and romped home 4-6, 6-1, 6-0. “First set, I lost. I was a little bit disappointed. I said, look, I’m going to fight again and see what happens. I found my game again,” said the hard-hitting Spaniard.

Muguruza, currently ranked eighth, is among several players in the running to reach this month’s eight-player WTA Finals in Singapore, where at least five places remain up for grabs.

Kvitova, who was hit by glandular fever this year and was visibly tired as she left court, confirmed she would play next week’s China Open as she bids to qualify for the WTA Finals.