She faced long games, hot conditions and a very dangerous opponent, but Petra Kvitova overcame them all. What did the World No.4 say was the key to the victory?
WTA Staff

MELBOURNE, Australia - Clearly benefiting from her enhanced off-season training and the work she's been doing with new fitness coach Alex Stober, Petra Kvitova powered past Mona Barthel and some hot, humid conditions at the Australian Open on Thursday to move safely into the third round.

She had to grind through some long games, including a 15-minute service game mid-way through the second set, but the No.4-seeded Kvitova kept her intensity up and just kept on playing her big game, eventually closing the German out after an hour and 19 minutes over on Hisense Arena, 6-2, 6-4.

Kvitova hit 30 winners to 21 unforced errors in the match. Ten of those 30 winners were aces.

The World No.4 was asked afterwards why she looked as fresh as ever after the 15-minute game.

"Fitness," Kvitova said with a smile. "I think it was quite warm out there today and I think I handled it quite well. I'm not sure if I would be able to handle it a year or two years ago. It was a very difficult game, and after the game it was difficult to stay in the set without a break, and of course it's always a little bit tough to breathe when it's really warm like that. And I felt a bit tired after that one game.

"But it was okay because I had that many times during my off-season, so I knew I could still play this time. Things weren't perfect out there, but I was able to win in the end, and that was good."

Stober is Li Na's former fitness trainer - was it tough for Kvitova to adjust to his techniques?

"When we started, the first three or four days were very, very tough. I felt everything. I couldn't really walk. It was probably funny to see me. But I think that every day when he would do his treatments, I could handle it more and more, and more practices probably, and tougher workouts.

"It's giving me some more confidence again. But every match is still very tough."

Awaiting Kvitova in the third round on Saturday will be Madison Keys, who stormed back after losing the first set to get past No.29 seed and Aussie home favorite Casey Dellacqua, 2-6, 6-1, 6-1.

Kvitova beat Keys in their only previous meeting, though that was back in 2013.

"For sure she's a better player than she was when I played her in Tokyo," Kvitova said. "It's also a different surface and different conditions, for sure. I know she has a big serve, and she's going to be really aggressive, so that's why I just have to serve well and try and return her serve well."