“I’m trying to play 100 percent — which I was close today — to run normal, and to run a lot,” Halep said. “But I still feel it. It’s there, but I can handle it.”
In the last match of the day’s schedule, which stretched more than an hour into Tuesday morning, Pliskova won, 6-7 (5), 6-3, 6-2, over 20th-seeded Barbora Strycova, a fellow Czech.
Pliskova hired away Strycova’s coach, Tomas Krupa, in the off-season, which Strycova countered by hiring Pliskova’s previous coach, David Kotyza. The swap led to a frosty atmosphere at the Prague club where they both trained, but the players were able to keep that subplot on the sidelines in their first encounter since the changes.
“I was just trying to play my game,” Pliskova said. “Because I know if I would get into it and think about what everything happened with the coaches and with her, I would not be playing the best. I think this I did perfect. I was just really focused on my tennis, not on the things around.”
That composure led the Open’s on-court interviewer, Rennae Stubbs, to describe Pliskova as “cool as a cucumber.” The idiom bemused Pliskova, who later said that she would have to turn up the heat of her game in order to hit through Halep’s relentless defenses in the next round.
“I have to get my mind-set ready for this,” Pliskova said.
There will be a similar challenge for Keys against Kerber, in a comparable battle of puncher versus counterpuncher.
“I think she has an ability to cover the court and anticipate like really no one else does,” Keys said of Kerber. “So, for me, it’s having to play aggressive but also consistently aggressive, because I know she’s going to make three more balls than other girls may be able to get to.
“So it’s not feeling rushed and that I have to go for something crazy-big on the first one. Just really work the point.”
Kerber, who has won six of seven matches against Keys, appeared burdened by the No. 1 ranking she carried for much of last year. This year, seeded 21st, she has played more freely, and she will be seeking her 14th consecutive victory.
“I just enjoy my tennis again,” Kerber said. “I think this is the most important thing for me when I’m on court: that I fight, that I play my game.”
In Tuesday’s quarterfinals, fourth-seeded Elina Svitolina will face Elise Mertens, who is in the final eight of a major for the first time, and second-seeded Caroline Wozniacki will play Carla Suárez Navarro, a former top-10 player who has fallen to 39th in the rankings.