Naomi Osaka was driven by the prospect of facing her idol, Serena Williams, in the US Open final as she overcame Madison Keys to make history at Flushing Meadows.

At the age of 20, Osaka became Japan's first female grand slam finalist in the Open era courtesy of a 6-2 6-4 victory over Keys, last year's runner-up.

She will now meet 23-time slam singles champion Williams, who won her first title in New York 19 years ago and thumped Anastasija Sevastova prior to Osaka's win over Keys on Thursday.

The scoreline of the second semi-final was not reflective of a hard-fought contest, with Keys earning 13 break points but failing to take any of them.

In an on-court interview with ESPN, Osaka was questioned on how she continued to deny her opponent a break and provoked laughter with her response.

"This is gonna sound really bad, but I was just thinking I really wanna play Serena, said Osaka, who has frequently spoken of her respect for Williams.

Asked why that was the case, she added: "Because she's Serena!"

Saturday's final will now provide a tantalising contest between one of the game's rising stars and its most dominant figure.

Osaka was invited to give a message to Williams ahead of the showdown and whispered: "I love you," sparking further hilarity on Arthur Ashe Stadium.