WATCH: Giant-killer Daria Gavrilova

The relentless 21-year-old knocked out world number six and double Wimbledon champion Petra Kvitova on Rod Laver Arena on Wednesday evening -- her fourth top-10 scalp in the last year.

Gavrilova, who was born in Russia and only became a naturalised Australian in recent weeks, said she always felt an upset was possible.

"Coming into this match I was pretty confident that I could beat Petra," said Gavrilova, who also stunned then-world number two Maria Sharapova in Miami last year.

"I knew that she didn't have enough matches before. She didn't even play anything before Oz Open. So I thought it was a good chance."

The Czech sixth seed had no answers to the confident Gavrilova, who raced into a Grand Slam third round for the first time, winning 6-4, 6-4.

Kvitova's demise followed the early exits of second seed Simona Halep, eighth seed Venus Williams and former world number one Caroline Wozniacki.

While those established names are on a plane home, Gavrilova has been joined in the third round by a host of younger players.

They include her next opponent Kristina Mladenovic (22), Monica Puig (22), Belinda Bencic (18), and Yulia Putintseva (21), to name a few.

Veteran superstars Serena Williams and Maria Sharapova continue their relentless march, but Gavrilova said she sensed the tide was turning for the younger generation.

"There are so many girls now coming through. I'm not going to name them all. But already this week there are a few in the third round. It's great," she said. 

"We're all excited. We're all pretty friendly. We hang out together. Yeah, like I said, we're all supporting each other. I think it's going to be awesome.

"A few girls have already made the second week, even made semi-finals (of Grand Slams)," she added, such as Eugenie Bouchard and Garbine Muguruza. 

"So I think a lot of us who haven't made it are thinking about it. Really it motivates us."

Former world number one Ana Ivanovic, 28, was in a similar situation eight years ago, when she won the French Open in 2008 as a 20-year-old.

Now an established player, she is excited to see so much new talent coming through.

"It's completely different to when I started," she said, after beating Anastasija Sevastova to reach the next round.

"I remember being seeded, you would get to third, fourth round without dropping too many games. So if you had 6-4, 7-5, (people) were like, 'What's going on?' 

"And now every match it's a battle, and you just have to try and push yourself, because it's all a challenge. They are young girls and they're fearless."

Gavrilova now stands alone as the last Australian woman left in the singles draw and she is feeling the Aussie spirit -- even down to her fingernails, which were painted with Australian flag designs.

The Moscow-born player is already a hit with home fans, with Thursday's Herald Sun newspaper calling her: "The new Aussie we've fallen in love with."

"I came here when I was about 15 and always loved coming here. I don't know if you know, but I had a boyfriend. We've been together for a long time," she said. 

"He's Australian. I live here, so... This is I guess a big reason why."

AFP

WATCH: Daria Gavrilova interview following Kvitova victory