“I know how many great players are still in the draw and playing great and everything,” she said, after beating Canadian Leylah Fernandez in the second round.
“I'm not a clay player, anyway. I mean, I'm enjoying playing on the clay, I grew up on the clay, but definitely there is more kind of specialists of the clay players here in the tournament.”
Zhang is the first player from China through to the fourth round since former champion Li Na in 2012.
“Always tough on clay for the Chinese player or Asian player because we play good on faster court,” said Zhang, who has beaten Kvitova twice in five career meetings.
Djokovic on a roll
Djokovic, the 2016 champion, has been in fine form, reaching the second week with the loss of just 15 games.
”If you impose yourself from the very beginning on the court, which I have in those first three matches here, then it makes it hard for them to really believe that they can come back and make a turnaround in the match,” said Djokovic after dispatching lucky loser Daniel Elahi Galan of Colombia, 6-0, 6-3, 6-2 in the third round.