It was late afternoon on day one of Wimbledon 2019 that the big wide world woke up to Coco Gauff. Some had gained awareness of the (then) 15-year-old American schoolgirl just a couple of days before, when she achieved the historic mark of becoming the youngest player in the 51 years of the Open era to earn a main draw Wimbledon berth by coming through Qualifying.

Then the draw duly obliged with a storybook first round against Venus Williams. Who could resist? With the gifted youngster facing a five-time champion of SW19 - two of which victories pre-dated Gauff's birth - a charming confection was on the cards, concluding surely with Venus's 90th career match win at Wimbledon.

But on No.1 Court, the anticipated gawky teenager failed to show. Instead, those of us courtside witnessed an assured young woman deliver a display of breathtaking poise to create an utterly sensational upset.

The world No.313 nervelessly triumphed 6-4, 6-4 in 79 astounding minutes, overawed neither by her opponent, the stage, nor the capacity crowd. Only victory itself floored her.

"This is the first time I ever cried after winning a match," Gauff said, before giving a tiny reminder of her age. "The last time I cried was watching Avengers: Endgame when Iron Man died. I really liked Iron Man."

Her Wimbledon odyssey rolled into the second week and the last 16, where it took the eventual champion Simona Halep to halt "the young one" as the Romanian referenced her. Two years down the line and the former junior world No.1 is barely past her 17th birthday - indisputably still "the young one" and indeed younger than any other player in the top 350.

Yet she arrives at Wimbledon 2021 with her first Grand Slam quarter-final under her belt from Roland-Garros earlier this month (it took the eventual champion to stop her there too, in the form of Barbora Krejcikova), and a world ranking which has leapt to 23.

Back in 2019, her escapades on the greensward of SW19 prompted a global chorus hailing her as a dead-cert future great of the game. Many appeared to imagine that Gauff's success at such an early age made it inevitable that the sport's premier prizes would be heaped around her feet in no time, as if in a couple of years all she would have to do was to turn up and multiple Grand Slams would be hers.

This entirely overlooked that it was precisely her youth which left as much opportunity for progress to founder, because nothing is certain in elite tennis - apart from which it completely disregarded the skill and determination of any other player.

This bigger picture makes her steady climb thus far even more remarkable. Two months after her Wimbledon derring-do in 2019, she reached the third round of the US Open where - spot the recurring motif - she was stopped by the eventual winner Naomi Osaka.

But in a repeat encounter at the Australian Open last year the tables were sensationally turned, as Gauff upended the defending champion in straight sets. By then she had secured her first WTA title, in Linz (the youngest WTA tournament winner since 2004), adding her second on the Parma clay just two months ago.

In Eastbourne this week, in her first outing on grass for 23 months, she lost the first eight games to the higher-ranked Elise Mertens before forging her way into the second round, where she succumbed to world No.61 Anastasija Sevastova. Nothing is a given, in tennis.

Gauff's return to Wimbledon, scene of that 2019 global breakthrough, will prompt huge attention, her every point analysed for conclusive signs of where she is heading. One observer who has no doubt is Tracy Austin.

"She will be a sensation again," forecast the double Grand Slam winner and twice Wimbledon semi-finalist. "Two years on, her forehand and second serve have improved, and she is so much stronger. She has a wealth of experience and has now won titles. She is going to go back there as a seeded player, and she is going to go deep."

As for Gauff, her own words from the day she announced herself on the global stage still carry resonance. "I wasn't surprised that I won," she said in the post-match press conference.

"I think people limit themselves too much. I like to shoot really high. We're all going to die one day, and I want to make the most of it all."