SONAY KARTAL produced the biggest victory of her career over Mirra Andreeva to reach the China Open quarter-finals.

The 23-year-old from Brighton battled to a 7-5 2-6 7-5 win against world number five Andreeva in Beijing to continue her stunning week.

It is the first time Kartal has beaten a top-10 player and the first time she has reached the last eight at a WTA 1000 event, while her success will see her overtake Katie Boulter as British number two.

Kartal’s composure proved crucial in a contest full of entertaining rallies that was on a knife edge until the end.

The pressure got to 18-year-old Andreeva in the final game of the opening set and, although she hit back strongly in the second, Kartal kept her nose in front in the decider with some exceptional play.

Andreeva had been holding her own serve fairly comfortably but at 5-6 the occasion told again and the Russian’s disappointment was evident after she dumped a forehand wide to hand Kartal victory on her second match point.

Kartal, who will next play 26th seed Linda Noskova, said in her on-court interview: “She’s a top-10 player for a very good reason, she made me play my best tennis today. I’m super happy with the level I managed to dig it out in the end.

“I think the way I carry myself on the court is one of my biggest assets. You could look down the other end at me and you wouldn’t really know if I’m winning or losing.

“I just tried to put that second set behind me. She played some great tennis so I just tried to level it out in the third set and keep the scoreboard pressure as high as I could.”

Emma Navarro caused another big shock by knocking out top seed Iga Swiatek.

The US's Navarro, seeded 16th, had not won more than three games in two previous matches against Swiatek, but she turned the tables to triumph 6-4 4-6 6-0.

It was an erratic performance from the Pole, who lost a love set for the third time this season.