Japan's Naomi Osaka overcame 23-time Grand Slam singles champion Serena Williams in a dramatic US Open final to clinch her first major title.

Twenty-year-old Osaka, competing in her first Grand Slam final against her childhood idol, defeated Williams 6-2 6-4 after the American was docked a game by umpire Carlos Ramos with the Japanese player leading 4-3 in the second set.

Williams had earlier been given a warning for on-court coaching and was then given a point penalty for racket abuse before being given a game penalty for an outburst in which she called Ramos a thief.

The drama should not take away from what was a fantastic performance by Osaka to break through to her debut major win but the Japanese player was visibly moved by the home crowd's boos during the trophy presentation.

"I'm sorry it had to end like this," said an emotional Osaka. "It was always my dream to play Serena in the US Open finals so I am really glad I was able to do that."

Osaka follows in the footsteps of Japan's Shigo Kunieda and Yui Kamiji, both of whom have won multiple Grand Slam singles titles in wheelchair tennis, but will go down in history as the first player from her country to win a major in the main draw.