Japan's Naomi Osaka has won the Australian Open for her second consecutive Grand Slam title by beating Petra Kvitova 7-6 (2), 5-7, 6-4 in the final.

The 21-year-old Osaka also becomes the first tennis player from Japan to reach number one in the rankings.

Osaka held three match points at 5-3 in the second set but couldn't close it out. She allowed Kvitova to come back and win 23 of 27 points to take that set and go up 1-0 in the third.

But Osaka regained her composure and her big-shot ability down the stretch, breaking to lead 2-1 with a cross-court backhand winner and holding on the rest of the way.

Osaka added this trophy to the one she collected by beating Serena Williams in a chaotic US Open final last September.

Osaka is the first woman to win two major championships in a row since Williams picked up four straight in 2014-15.

Japanese Prime Minister Shinzo Abe congratulated the 21-year-old.

"The thrill of a hard-fought victory! Congratulations on winning the Australian Open, Naomi Osaka," Abe wrote on his official Twitter page.

"I am very proud of the emergence of a new queen. I look forward to your continued accomplishments."