WASHINGTON, Aug. 22 (Xinhua) -- Three-time champion Petra Kvitova of the Czech Republic moved into the quarterfinals in Connecticut Open for the sixth time in her career after a 6-1, 5-7, 6-2 victory over qualifier Zarina Diyas of Kazakhstan on Wednesday.

Kvitova said: "The center court is probably a little bit faster than other courts. It's a quiet place which I always love -- it's a calm before the storm coming in New York, so it's a great place to be. I just feel very good here, very relaxed, enjoying the time here."

No.3 seed Kvitova and Diyas had split their two previous meetings, but it was Kvitova who survived a tight second set and a stern challenge from Diyas to take the match in just under two hours, in their first-ever battle on hardcourt.

"Of course, I wanted to make it in two sets, but unfortunately, that happens sometimes," said Kvitova. She continued by saying that "luckily, I came back in the third one -- from the beginning of the third set I was there, and it was important to play each point."

Kvitova has played 21 three-set matches this season, winning 17 of them, more than anyone else on the WTA in 2018. "I'm just fighting in the third sets," explained Kvitova. "It's about fighting in the third, I think. It's just about a couple of points to win it."

"Of course at the end of the season you have a lot of three-setters, and I'm just glad that I do have a better percentage in them," Kvitova continued. "It's not the first or last season like this, I've had so many three-setters before as well. I'm just kind of always putting so much effort in the third, I know it's decided there."