Petra Kvitova produced her best grand slam form since her career-threatening hand injury to set up a fourth-round clash with US Open favourite Garbine Muguruza.

Kvitova has understandably struggled on the North American hard courts this summer as she continues to come to terms with what happened to her last December, when she was stabbed by an intruder at her home in the Czech Republic.

Having gone into Wimbledon improbably as one of the favourites and lost in the second round, Kvitova arrived in New York with little expectation on her shoulders.

And it appears to have benefited the 13th seed, who is yet to drop a set despite a tough draw, and defeated Caroline Garcia 6-0 6-4 in round three.

Kvitova said: “Sometimes I do feel a little bit more normal than before, especially on the court and around players and people, around tennis, which I’m very grateful that I can be part of it again.

“Life is still a little bit strange, but it’s getting better. Hopefully one day it will be better.

“I do feel much better and closer to my top level. I think that I really played great today. I’m still not there, for sure. I think still my hand is not 100 per cent ready, so I do feel hopefully that I have space to improve.

“But on the other hand, I will be very lucky if I am playing like this every day. I’m more pleased now that I know it’s still there.”

Kvitova has beaten Muguruza in two of their three previous meetings, but the Wimbledon champion is looking in ominous form.

Muguruza has not yet come close to dropping a set and defeated Magdalena Rybarikova 6-1 6-1 on Friday in a repeat of their Wimbledon semi-final.

Kvitova will face a top-10 player for the first time since her comeback in May and is looking forward to the challenge, saying: “That’s means I’m kind of deep in the tournament, finally

“It’s nice to play someone who won a grand slam this year. I’m really looking forward for the big stage and for that match.”

Muguruza’s victory means the race to be world number one at the end of tournament has narrowed to three, with Simona Halep and Venus Williams eliminated.

Only current incumbent Karolina Pliskova, Muguruza and Elina Svitolina can now top the standings.

Muguruza arrived in New York having never been beyond the second round but is looking more and more the likely champion with every match.

She said: “I feel I’ve improved a lot as a tennis player. The summer has been great, and I’m playing a lot of matches. So the fact that I played so many matches gives me pretty good confidence.”

Williams made it through to the fourth round for the 15th time in 19 attempts with a 6-3 6-4 victory over Maria Sakkari despite serving a whole game of double faults early in the second set.