Zheng stuns Swiatek at US Open as Andreeva extends winning run

Chinese qualifier Zheng Qinwen produced another spectacular fight back to upset six-times major winner Iga Swiatek 7-5 6-3 in the US Open on Monday, recovering from 0-5 down in the opening set to reach the quarter-finals.

The Olympic champion battled her way through qualifiers amid a career slump and has recaptured her top form in New York, getting the best of an opponent who had led 7-to-1 in their head-to-head before Monday.

"I have to say I start the match not so well and after little by little I found my rhythm," said Zheng, whose chronic right elbow injury stunted her career and forced her to undergo surgery last year.

"I just focused point by point and little by little I started to play better tennis."

She next plays either Naomi Osaka or Elena Rybakina.

Zheng appears to do her best work with her back against the wall, recovering from five games to love in the deciding set of her third round match this week, and she found the magic again at Arthur Ashe Stadium, saving three set points to the increasing frustration of the 2022 champion Swiatek.

Swiatek took a medical timeout after the third game of the second set, having a physio come and massage her left thigh, but did not appear to struggle as she returned to the court.

Zheng broke her opponent with a backhand winner down the line in the seventh game and broke again on the fourth match point, leaving Swiatek in tears again two years after she stunningly beat the Pole in the Olympic semi-finals.

Elsewhere, Russian fifth seed Mirra Andreeva fought back to beat Austrian Anastasia Potapova 5-7 6-4 6-3 and extend her deepest run at the US Open into the quarter-finals.

The 19-year-old Andreeva had her opponent on the ropes when Potapova went down with an apparent leg injury late in the match, putting a disappointing end to an otherwise competitive affair.

"She's my good friend and seeing what a battle we had... seeing her fall like this, it's not easy," said Andreeva. "It's not the way obviously you want to finish the match... I just told her she's been playing amazing so far."

The Roland Garros winner will next play the winner of an all-American clash between Iva Jovic and Coco Gauff.

Potapova put up less than half as many unforced errors as her opponent in a tightly fought opening set, where Andreeva could not hang on when it counted the most, helping her opponent to the critical break in the final game with two double faults and a misfiring backhand.

But the Russian cleaned up her form considerably in the second set, thriving in the shorter rallies before Potapova handed over the decisive break with a double fault in the seventh game.

Andreeva broke her opponent from the baseline to go up 2-1 in the final set, where Potapova collapsed onto the court clutching her left knee in pain after chasing a ball along the baseline in the ninth game. Andreeva ran to her aid and helped her limp to her bench.

She lay on the court for several minutes as a physio taped up her leg and valiantly finished the match, as Andreeva clinched it with a backhand winner before going to the other side of the court to embrace her opponent.

"She's a better fighter than me so I'm sure she's going to come back even stronger," said Andreeva.