Karolina Pliskova expects Coco Vandeweghe to provide a different test to anyone else she has faced at the 2017 US Open but the world number one is ready for the challenge.

Pliskova eased into the quarter-finals on Monday with a comfortable straight-sets victory over Jennifer Brady, the top seed needing just 45 minutes to race to a 6-1 6-0 triumph.

The Czech described the performance on Arthur Ashe Stadium as her "best" of the year, leaving her in confident mood heading into the latter stages of the tournament.

Next up is American Vandeweghe, who registered a 6-4 7-6 (7-2) win over Lucie Safarova, and Pliskova knows she faces a tough battle to reach the last four.

"I think she was playing very well," Pliskova said when asked about Vandeweghe.

"I guess she just loves the crowd and the big stage, so she's always going to play well here on centre court. It will be tough.

"Obviously she has a big serve. It will be a different match to what I had so far this tournament, [there are] not many girls playing that fast and with that serve and that speed.

"I have to prepare. I have a day off tomorrow again, so I will just prepare for it."

Should Pliskova reach the final in New York she will retain the world number one ranking, but a first grand slam title would be even greater reward for the 25-year-old.

Compatriot Petra Kvitova may have something to say about that, though, after she dumped Wimbledon champion Garbine Muguruza out in round four - a win that impressed Pliskova.

"I saw a few games, I think she was playing very well," she said.

"She's still a big player Petra, so she can play those big matches like she played yesterday [against Muguruza].

"Night session is a perfect time for her. I think she was just much better in that match and Garbine was not her best.

"It was an important win for Petra."