Petra Kvitova says her aggressive style of play is back after stunning Garbine Muguruza in the fourth round of the US Open.

Kvitova stuns Muguruza in New York

Kvitova stuns Muguruza in New York

Kvitova, who returned to action in May following a knife attack at her home last December, managed to overcome the third seed at Flushing Meadows to book her place in the quarter-finals for the first time since 2015.

The Czech, who required extensive surgery on her left hand following the incident last year, battled back from 4-1 down in the first set to win the match 7-6 (7-3) 6-3 in Sunday's night session.

It was a terrific performance from the 27-year-old two-time Wimbledon champion and she will now take on American Venus Williams, a two-time winner of the final Grand Slam of the season, after she ousted Carla Suarez Navarro in three sets, winning 6-3 3-6 6-1.

Kvitova appears to have rediscovered her best form and she admits it is pleasing to be able to perform to such a high level, especially after revealing only last week that her hand did not feel completely back to normal.

"Sometimes I just really feel that the touch is there - the strength, the aggressive kind of game plan," she was quoted as saying by BBC Sport. "It's there, which I really, really appreciate. It took me a while to find it. Luckily I found it in a Grand Slam, which is nice."