"Of course, it's hard to take, it's hard to put into words at the moment," Barty said.
"It was a hellish week, I could not leave the field anymore, and Petra arrived
" Sometimes when you play Petra you have those games, in which most of the time it's out of my control. He had the courage and was brave, in that buster [tiebreaker] in particular, to play the game. He deserved to win today. "
Despite the disappointment, Barty will head to Melbourne with the wind behind him and will face the Thai Luksika Kumkhum, ranked in 66th place in the world, at the Margaret Court Arena, Monday evening.
The 22 year old has exploited the first set in 26 minutes, breaking the Czech's service three times with his game across the board to close the 6-1.
Kvitova looked troubled by her right thigh or hip and can even fight her tiredness after the rain delayed his semifinal clash with Aliaksandra Sasnovich for almost five hours Friday night, the fifth seed eliminated the Belarusian qualification in less than one hour but is not a given in the field until midnight.  She recovered to find a little bit of rhythm then a little bit of domination, the second set turned into a "tit-for-tat" clash, both women won their games of service until the 28 year old broke Barty and then took the 7-5 set.
The third set went to a tie-break after both women broke the service of the other three times. Kvitova seems to have struggled in hot conditions and produced two double fouls but took the 7-3 tie break when Barty lost his championship lead.
Loading  "I stayed in the game," Kvitova said. "He played very well from the start, I was very lacking, I was just trying to go back, keep the service and maybe wait for the opportunity that, at the end of the second set, it arrived and I I set myself up and down, down for a break, but I still believed in myself that I could do it. "
Barty did not suffer from his opponent's unease and paid tribute to Kvitova's" courage ".
"I noticed towards the end she looked a little bit gassed and took some extra risks and they paid for her. She had the courage to do it, I have to give it a tap, today she played an extraordinary match. "
The La ceca said he was fighting in the first set and suffered cramps in the third, producing two double fouls in a row to bring the game to the tie-break.
"It was such an amazing ending, I was really down, very slow, since I'm happy to find a way to win somehow," he said.
"It was a lot of nerves, even some cramps, it was all one, but it's beautiful."
Georgina Robinson is the leading rugby journalist for the Sydney Morning Herald.