Kvitova silences 'soccer' crowd to beat Sakkari

Petra Kvitova compared the atmosphere created by Greek Maria Sakkari's supporters on Rod Laver Arena to "a soccer match" but cut through the noise and battled back from a set down to reach the Australian Open quarterfinals on Sunday.

After Sakkari rode that boisterous support to a first set tiebreak win, Czech seventh seed Kvitova came firing back to clinch a quarterfinal place with the 6-7(4), 6-3, 6-2 victory.

"When I was shaking the hand with the umpire, I told him it was like a soccer match today," Kvitova told reporters of the atmosphere on the main showcourt.

"It's nice on one side. On the other side, it's the tennis, and it's not a Fed Cup.

"It's strange. But ... it didn't bother me at all."

It is the second time this week that players have noted the noise generated by Melbourne's large Greek community, who were also in full voice when supporting Stefanos Tsitsipas.

The men's sixth seed, however, has said there was a difference between the behaviour expected of tennis and soccer crowds and his own fans had probably crossed a line.

Sakkari, 24, had never been in the fourth round of a Grand Slam before but had won the last two of her three previous matches against Kvitova, all of which were played last year.

She broke early but blew her first chance to seal the opening set when she lost serve leading 5-4, but made up for it in the tiebreak when Kvitova wasted an opportunity to go 3-0 up.

Both players lost their serving rhythm in the second set with Kvitova dropping serve twice but also breaking Sakkari on four occasions, the last of which when the Greek double-faulted on set point.

Sakkari's shoulders appeared to sag during the set and she frequently argued with her support team sitting courtside.

Kvitova jumped out to a 3-0 advantage in the decider then let her emotions show for the first time in the fifth game, a bellow of celebration coming after a forehand winner put her 4-1 ahead.

The Czech completed the win when a Sakkari return smacked into the net, setting up a meeting with either top seed Ash Barty or Alison Riske, who play later on Sunday, in the last eight.

Kvitova said it had not been her best performance but was pleased with the way she managed to loosen up as the match wore on.

"I didn't feel the best. I was just too tight and everything was flying somewhere," she said.

"But with the time on court I just get probably used to and I started to play a little bit better, more free."