Osaka continued her quest for back-to-back grand slam titles with a fighting 6-2 4-6 6-4 win over Czech Karolina Pliskova after Kvitova ended the daring run of unseeded American Danielle Collins with a 7-6 (7-2) 6-0 triumph in Thursday's first semi-final.

While 21-year-old Osaka will be striving to become the first woman to land consecutive majors since the great Serena Williams in 2015, Kvitova is driven by vastly different reasons.

The 28-year-old is bidding to complete one of sport's most extraordinary comebacks after advancing to her first major final since being savagely stabbed in a career-threatening home invasion in December, 2016.

The two-times Wimbledon champion was told by doctors she'd likely never be able to grip a racquet again, let alone play professional tennis, after having several tendons shredded in her playing hand during the vicious attack.

"It means everything," Kvitova said after denying unseeded Collins in a somewhat controversial semi-final that started in blazing sunshine but finished under a closed roof at Rod Laver Arena after the Open's heat rule was applied.

"That's why I worked very hard to be in the finals of the tournament, the final of the major.

"Finally, I could make it deep into a major and I really enjoy a final and, whatever happens, I'm really very, very happy."

Collins was less than happy, though.

Accustomed to training in steamy Florida, the 25-year-old complained to tournament referee Wayne McEwen - to no avail - after officials ordered the roof closure at 4-4 in the opening set.

But with the temperature in Melbourne soaring to 38 degrees - and much more on court - McEwen had no option but to enforce the safety rules.

Collins won only two more games playing indoors as Kvitova swept past the American underdog in one hour and 34 minutes.

"I think I was happier than the fans that the roof closed," the Czech said.

"I like to play indoors, so it really helped me a little bit.

"It doesn't matter. It was kind of warm, but if it is open, I am still going to fight."

Already Japan's only grand slam singles winner after downing Williams in last year's explosive final at Flushing Meadows, fourth-seeded Osaka extended her streak at the majors to 13 victories by ending Pliskova's unbeaten start to 2019.

Australian Associated Press