Naomi Osaka stands at the top of women's tennis following her victory over Petra Kvitova in the Australian Open final.

The 21-year-old's 7-6 (2) 5-7 6-4 win earned her the world number one ranking and saw her become the first woman since Jennifer Capriati 18 years ago to follow up a maiden grand slam title by winning the next tournament.

Judging by what will surely be the first two of many slam finals, Osaka does not do routine. But, while her victory over Serena Williams at the US Open was about controversy and meltdowns, this time the drama was all on the scoreboard.

At a set and 5-3 with Kvitova facing three match points, Osaka looked poised to stroll over the finish line only to lose four games in a row and the second set.

She had lost her head, too, but one of the most impressive things about her this fortnight has been the way she has overcome every mental hurdle placed in front of her and so it proved again, as she refocused and powered her way through the decider.

Osaka had been in tears on the podium in New York as the deafening jeers rang around Arthur Ashe, and there were more tears at the end of the second set, but this time a much happier ending.

"I felt like I didn't want to have any regrets," said Osaka. "I think if I didn't regroup after the second set, then I would have looked back on this match and probably cried.

"I just thought to myself that this is my second time playing a final. I can't really act entitled. To be playing against one of the best players in the world, to lose a set, suddenly think that I'm so much better than her, that isn't a possibility.

"I literally just tried to turn off all my feelings. I just felt kind of hollow, like I was a robot sort of.

"I still feel very shocked. I felt like the match wasn't completely done, but it was done. It's one of those moments where you're fighting so hard. When it's finally over, you're still in the state of competitiveness."

Osaka went into the Australian Open 12 months ago ranked 72 and never having made it past the third round of a slam. She reached the last 16 here then went on to make her breakthrough in March by winning the big WTA title in Indian Wells.

While her progress appears to have been lightning fast from the outside, Osaka does not see it that way.

She said: "For me, every practice and every match that I've played, it feels like the year is short and long at the same time. But I'm aware of all the work that I put in. I know all the sacrifices that every player does to stay at this level. In my opinion, it didn't feel fast. It felt kind of long."

Osaka is the first Asian man or woman to top the singles rankings, so it was fitting that it was China's Li Na, the winner here five years ago, who presented her with the trophy.

"I didn't expect to see her there," said Osaka. "At first I was very shocked. I wanted to cry a little bit, but I didn't want to cry on the podium. I just felt really honoured."

Kvitova, who would also have become number one with victory, was playing in her first grand slam final since winning her second Wimbledon title in 2014 and only two years after the knife attack at her home that put her career in the balance.

The Czech could not hide her pain at the result but was able to see the bigger picture.

She said: "It's hurting a lot today. I wanted to win and have the trophy. But I think I already won two years ago. So, for me, it's amazing. I think I still don't really realise that I played the final."

Kvitova had to pause in her on-court speech for a standing ovation after thanking her team for standing by her when she did not know if she would ever be able to hold a racket again, such was the damage to the nerves and tendons in her fingers.

"I've been through many, many things, not really great ones," she said. "I'm holding it (the racket), so that's good. There's still a few things which I can improve, and we'll do it. So it's not the end. I'll be back for sure."