Japanese fourth seed Naomi Osaka reached another US Open final after producing a high-quality performance to edge past American Jennifer Brady.

Both maintained a high level at the start of the third before Osaka took control to win 7-6 (7-1) 3-6 6-3.

Osaka, 22, will play Serena Williams or Victoria Azarenka in Saturday's final.

Old rivals Williams and Azarenka play their semi-final later on Thursday at Flushing Meadows in New York.

If American third seed Williams wins, it will tee up a repeat of the final two years ago when Osaka won in one of the most extraordinary finals ever seen.

The Japanese player hid behind her visor as she cried during the trophy presentation after a tumultuous match where Williams accused umpire Carlos Ramos of being a "liar" and a "thief" amid angry scenes on Arthur Ashe Stadium.

Maturing Osaka earns another shot at US Open glory

Osaka backed up her maiden Grand Slam victory with another triumph at the Australian Open five months later, but then struggled to cope with the increased pressure of being the world's top-ranked player.

Now, after dropping to 10th before the coronavirus pandemic struck, she has returned looking again like a player who could go on to dominate the sport.

Osaka has matured as a person and player since her first Grand Slam wins, with new coach Wim Fissette acknowledging this week that her activism against racial injustice and police brutality in the United States has added further fuel to her mission of winning in New York.

A supreme confidence and a steely resolve has been key to her march through to the semi-finals, where she came up against an opponent with similar traits.

Both players excoriated the ball from the start on a near-deserted Arthur Ashe Stadium, hitting it cleanly and crisply in an opening set where both barely made a mistake.

Brady's path to a maiden Grand Slam semi-final had been unusual compared to most of her peers, having played in the American collegiate system before a relatively late progression to the WTA Tour.

Wayward hitting in the first-set tie-break appeared to suggest the magnitude of an occasion like she had never experienced before may have got to the 25-year-old.

However, she bounced back impressively in the second set as she reset mentally to rock Osaka when the two-time Grand Slam champion's level momentarily dipped in the eighth game.

Brady pounced for the break and then served out the set to deservedly take the match into a decider.

Both players had played arguably their best tennis of the tournament in the opening two sets and the only question going into the third was whether that level could continue.

Brady had not faced a break point in the opening two sets but suddenly saw her serve pinched from nowhere in the fourth game of the decider as Osaka took control for a 3-1 lead.

Nerves did creep in for Osaka as she tried to serve out victory, her ball toss going awry and leading to one double fault for 15-30, only to steady herself and clinch the win in two hours and 11 minutes.