Petra Kvitova described her last-four run at the Australian Open as "the first semi-final of my second career".

The Czech was in inspired form in a 6-1 6-4 beating of home favourite Ashleigh Barty on Rod Laver Arena on Tuesday.

It is the furthest Kvitova has gone in a grand slam since returning to the WTA Tour after she was the victim of a knife attack in her home in December 2016.

The incident left Kvitova with severe injuries to her playing hand and fearing for her career.

And the two-time Wimbledon champion, who was evidently emotional in her on-court interview, is revelling in the moment. 

Asked if it felt different to her previous grand slam semi-final appearances, she said: "It is, for sure. I'm calling it as my second career. So, it's the first semi-final of my second career. 

"It's took me a while, for sure. I never really played that well at the grand slams, so I'm happy this time it's different. I'm really enjoying it. The tournament is still not over yet."

Kvitova, who was last a semi-finalist in Melbourne in 2012, says her absence from the Australian Open two years ago helped her gain a new perspective on tennis and life.

"I think the year I didn't play here, I was watching TV when other players played. It wasn't really a great feeling to be honest," she added. 

"I really missed that a lot. I think I'm seeing life a little bit differently compared to before. I know it's just a sport, it's just tennis. 

"Always when you are doing something, you want to do your best. Of course, losing, it hurts a lot because you are doing everything for it. 

"On the other hand, like the day after, or me, I'm always looking back and seeing what has been done and what I achieved from the time. It's always both sides."

Awaiting next is surprise semi-finalist Danielle Collins, who had never gone beyond round one at a slam before this year's tournament, after the American defeated Anastasia Pavlyuchenkova in three sets.

"This has all been a really incredible experience," Collins said. "Obviously it's my first time playing the main draw here in Australia, so I think that's a little bit new to me. 

"This time last year I was playing a challenger in Newport Beach. I think I'm really embracing it."

Collins lost out in a three-set grind to Kvitova in Brisbane earlier this month.

"I've played Kvitova once a couple weeks ago and she's tricky because she's a lefty," she added.

"I followed a lot of her career. She's an incredible champion, has gone through a lot. We had a really great battle a couple weeks ago, one of the best matches I've played. I didn't even win that match."