NEW YORK – When Naomi Osaka was a girl, she dreamed of playing her idol in a grand slam final.

Now this fantasy has become a reality at the US Open. Osaka, 20, will face Serena Williams, 23-time Grand Slam champion, for the chance to become the first Japanese to win a Grand Slam title at the Open.

Osaka, 20th seeded, took a shot at Williams, 36, after defeating Madison Keys, last year's US Open finalist, 6-2, 6-4 in the semifinal on Thursday night. Williams, seeded 17th, had already reached its 31st Grand Slam final with a decision in the semifinals of 6-3, 6-0 over Russia's Anastasija Sevastova (19th).

"Of course, we feel a little surreal," admitted Osaka, about his first Grand Slam final. "Even when I was little, I always dreamed of playing Serena in the final of a Grand Slam. Just the fact that it's happening, I'm very happy with it.

"At the same time, I think that although I should appreciate this moment, I should still see another match. Yes, I should not really think of her as my idol. I should just try to play it as an opponent. "

When asked how the match ended in his dreams, Osaka seemed surprised that the conclusion was not a given.

"You already know it," she said with a smile. "You just ask me. I do not dream of losing.

The good news for Osaka is that she will not make it to the final without knowing how to play Williams, as she has a 1-0 lead in her career matches.

The bad news is that the first-round match they played at the Miami Open in March is accompanied by an asterisk. Yes, it was an official 6-3 and 6-2 win for Osaka, but it also appeared the first month that Williams was returning from maternity leave and was showing little form of championship.

At that time, Osaka was at the peak of his career, just after winning his first career title at the Indian Wells tournament.

"I really think I do not want to think too much about this game, so I'm not going to think it's so much better than in Miami," Osaka said. "I'm just going to play there. As I already know that she is a good player, I do not want to be surprised if she plays better or not. "

For her part, Williams would like to believe that she took some advice on Osaka during this defeat in Miami.

"It was good that I play it because I know how it plays now," Williams said. "I was breastfeeding at the time, so it was a totally different situation. That was what it was.

"I hope I will not play like that anymore. I can only ride this match.

Osaka, who has dual Japanese and American nationality, has a history in New York, which makes this tournament the closest to home Grand Slam.

Born in Osaka, Japan, of a Japanese mother and a Haitian father, the family moved to the United States at the age of 3, living with her paternal grandparents in the neighboring town of Long Island.

Eventually, the family moved to South Florida where Osaka and her older sister, Mari, were able to benefit from better tennis training.

For Williams, the US Open is a familiar territory. She has won the title here six times, and if she manages to win a seventh trophy, she will break the tie with Chris Evert for most victories of the US Open in the Open era.

Overall, Williams is much more at stake than Osaka.

The title would not only be her first Grand Slam as a mother, but also a 24th Grand Slam career. That would bring her even closer to Margaret Court, the Australian who currently holds the record for the most Grand Slam titles.