Gavrilova marches on in Australian Open

Daria Gavrilova continues to fly the flag for her newly adopted nation at the Australian Open, stunning sixth-seed Petra Kvitova to march on to the third round.

Gavrilova upset the two-time Wimbledon winner 6-4 6-4 in 89 minutes to book a date with Kristina Mladenovic in the last 32 at Melbourne Park.

The 21-year-old, who was born in Moscow but confirmed her switch of allegiances to Australia late last year, produced a sparkling display on Margaret Court Arena.

The win ranks as one of Gavrilova's best, perhaps behind only a defeat of then-world No.2 Maria Sharapova in Miami last year.

"It was unreal," Gavrilova said.

"I was so nervous at the end. I'm just really proud."

Gavrilova and Kvitova traded heavy groundstrokes in a high-quality meeting.

The effervescent Gavrilova was broken twice in the first set, lashing out each time.

She threw her racquet after a string of double faults to trail 2-3, and kicked a ball in disgust.

But each time she responded to break straight back, her fist-pumps becoming more frequent as she grew in confidence.

In faultless end to the set, Gavrilova won three games without dropping a point to carry all the momentum into the second set.

A key moment then arrived at 2-3, with Kvitova twice double faulting and making two errors to give away her serve.

Gavrilova served for the match at 5-3 but wobbled, losing the next three points to put the match back on serve.

In front of a vocal crowd, Gavrilova calmed her nerves and broke straight back to reach the third round of a major for the first time.

While Gavrilova's effort would have troubled Kvitova at her very best, the towering Czech was not near it.

The world No.6 came to Melbourne Park with a lack of match practice, having pulled out of tournaments in Sydney and Shenzen with a gastro-intestinal problem.

The Czech joins world No.2 Simona Halep and No.8 Venus Williams as high-profile early departures from the tournament.