Competing at the scene of her traumatic maiden grand slam triumph in front of a crowd predictably and passionately backing a star American opponent, it would have been easy for Naomi Osaka to crumble in the third round of the US Open.

The defending champion and world number one had all the pressure on her shoulders in Saturday's blockbuster clash with 15-year-old Coco Gauff, who comparatively had nothing to lose after again capturing the sporting world's imagination with two thrilling wins.

Rather than wilting at the venue where she had been left in tears 12 months ago, Osaka rose to the occasion in stunning style, delivering a show of class on and off the court that should secure her place as a favourite in the hearts and minds of fans, as well as a frontrunner for the title.

From the start, Osaka played with confidence and ruthlessness, racing into a 3-0 lead. Rather than being overawed by the stage, she rose to it with the enthusiasm of a player with two major titles to her name.

Gauff threatened a comeback as the teenager found her footing, but she was never able to locate the consistency needed to restore parity against a player operating at Osaka's level.

After clinching the opening set, Osaka was relentless, refusing to let up as she condemned Gauff to a bagel in the second.

Osaka got 91 per cent of returns in play, converted six of her seven break points and hit 24 winners to Gauff's eight.

Pirouetting as she won one point to set up a break chance, Osaka operated with more freedom as Gauff faded and the gulf in experience and quality became more telling.

Yet nothing Osaka produced on the court could top what she did after the match, as she persuaded a tearful Gauff into staying behind to be interviewed alongside her in front of the packed crowd.

Both players ended up reduced to tears, but those shed will be remembered as part of one of the indelible moments of US Open history. A marked contrast to those Osaka wept last year as Serena Williams' row with umpire Carlos Ramos overshadowed what should have been the greatest night of the Japanese's career.

Gauff could not have been more appreciative of the gesture, and summed up Osaka's evening on and off the court perfectly.

"For me the definition of an athlete is someone who on the court treats you like your worst enemy but off the court can be your best friend," Gauff said. "I think that's what she did."

Discussion over Osaka's slightly withdrawn nature and lack of comfort in the spotlight has been a prominent feature of her rise to the top of the women's game.

Now the focus has been shifted to her capacity for empathy and her sportsmanship, though Osaka appeared to indicate she would still rather not be the subject of such attention.

Asked if the tennis world needs more "Naomi moments", Osaka replied: "I don't know what a Naomi moment is. Hopefully there won't be many of those. Yeah, whatever I do, I try to tell myself to just do it from the heart."

If she maintains the kind of form she demonstrated on Saturday, there is a strong chance the next Naomi moment will be her lifting the trophy.

Following her wonderful display of compassion for Gauff, the New York crowd that booed as she collected the trophy last year will surely this time be on her side should she prevail again.