Photo/IllutrationNaomi Osaka, of Japan, celebrates after defeating Madison Keys in the semifinals of the U.S. Open tennis tournament on Sept. 6 in New York. (AP Photo)

NEW YORK--Naomi Osaka announced her arrival on the big stage at the U.S. Open on Thursday, beating last year's runner-up Madison Keys 6-2 6-4 to reach her first Grand Slam final.

The 20-year-old Japanese will face six-times champion Serena Williams in the final at Flushing Meadows on Saturday.

Osaka, who is the first Japanese woman to reach the final of a Grand Slam, had to fight harder than the score suggested to get past 14th seed Keys, who paid the price for a lack of killer instinct.

The American carved out 13 break point opportunities, but Osaka saved all of them and was far more clinical herself, converting three of the four chances that came her way.

"This is going to sound really bad, but I was just thinking I really want to play Serena," Osaka said in an on-court interview. "I love you (Serena). I love everybody."

Osaka won her first career title at Indian Wells this year but had never beaten Keys before in three attempts and lost to the American at Flushing Meadows in 2016.

"It still feels really weird because I've never beaten Madison before," Osaka said. "She's a really good player ... I thought I was visibly shaking and stuff (from nervousness)."

The nerves surfaced when the Japanese found herself trailing 0-40 in her second service game, but she managed to keep it together, battling back to deuce and saving another break point to hold and level the opener at 2-2.

The roles were reversed in the next game.

Osaka carved out two break points and although Keys saved the first one, she forced an error on the American's forehand to take a 3-2 lead.

The Japanese saved two more break points in her next service game and then it was Keys's turn to get rattled.

The American made three unforced errors as she lost her serve to love. Osaka found herself serving for the set and she closed it out in 37 minutes.

"I felt like if I could break, maybe I could get back into it," Keys said. "Every time I had a break point, it was an ace or a winner or something like that (from Osaka).

"You keep fighting ... then for her to come up with some of those shots, it was difficult ... You think, okay, she's going to let up eventually, but she didn't, so all credit to her."

Keys emerged for the second set with an air of determination but she surrendered her serve in the first game with her 21st unforced error of the match.

That was the tipping point and Osaka wrapped up the win in one hour, 26 minutes with a service winner, breaking into a smile as the ball flew off the frame of Keys' racquet and into the crowd.