Leylah Fernandez and Emma Raducanu have taken New York by storm: Saturday's US Open final is one that nobody would have predicted and nobody should miss.
The teenagers from Montreal and London are ranked at 73 and 150 by the WTA, which runs the women's tour, and have sent a clutch of household names scuttling for the Flushing Meadows exits.
In the absence of the familiar formidable presence of Serena Williams, this remarkable duo have taken the grand slam by the scruff of the neck and made it their own, thrilling crowds with their bravura.
Ahead of their clash in Saturday's final, where a life-changing title is up for grabs, Stats Perform looks at how Fernandez and Raducanu have come so far, and the feats left for them still to achieve in the Big Apple.
RADUCANU ON A ROLL, MAKING HER FIRST MILLION
It was no secret in British tennis circles that Raducanu was a bright talent, but she prioritised her studies ahead of going on tour and this year's Wimbledon marked her first senior grand slam main-draw appearance. Precocious potential often goes unfulfilled, but Raducanu proved she had the game as well as the wit to handle the big stage as she powered through to the fourth round at the All England Club.
She still had not climbed far enough in the rankings to earn an automatic place in the US Open, so won three qualifying rounds to earn her place. Astonishingly, she has since lost just 27 games in six main-draw matches and has not dropped a set. Serena Williams was the last player to win this title without losing a set, losing 32 games in her 2014 campaign.
The 18-year-old is the first qualifier in tennis history to reach a grand slam final, and just the second woman to reach a final after fewer than three appearances in the majors, after Pam Shriver at the 1978 US Open, her second slam. Shriver lost in her final to Chris Evert, so Raducanu can set a women's tour record for winning a title at the earliest point of a grand slam career, in those terms.
Raducanu is the second Briton to reach the women's final in New York in the Open Era, after 1968 champion Virginia Wade, who has been in the New York crowd this week.
The youngster's career prize money stood at $303,376 before this tournament, and she will become a tennis millionaire whatever the result of the final. The winner takes away $2.5million and the runner-up collects $1.25million.
Previously coached by Andy Murray's father-in-law Nigel Sears, Raducanu has been working under the guidance of former British tennis player Andrew Richardson in recent months, and this run has made her the youngest women's grand slam finalist since a 17-year-old Maria Sharapova took the title at Wimbledon in 2004.
At the US Open, she has become the youngest player to reach the title match since 1999, when a 17-year-old Serena Williams beat Martina Hingis to land the first of 23 singles slams to date.
She is the lowest-ranked player to reach a women's US Open final, besides Kim Clijsters who was a former number one but unranked after coming out of a short-lived retirement to triumph at the 2009 tournament.
FERNANDEZ FLOORS THE STARS, BUT CAN SHE RATTLE RADUCANU?
While Raducanu can count Olympic champion Belinda Bencic among her victims, it has been Fernandez who has been the real giant-killer over this fortnight.
Since making an unassuming start with wins over Ana Konjuh and Kaia Kanepi to reach round three, Fernandez's run has gone into overdrive.
Sinking defending champion Naomi Osaka marked the kick-starting of one of the great charges through a draw, as the Japanese star became the first of three top-five stars to lose to the youngster, Elina Svitolina and Aryna Sabalenka being the others.
Fernandez, who turned 19 on Monday, overcame former US Open winner Angelique Kerber, too, and each of those four wins from the third round on has been epic, going to three sets each time and chock-full of tension.
She has become the youngest player to beat more than one player from the top five at the same slam since Serena Williams saw off Monica Seles, Lindsay Davenport and Hingis from the quarter-finals onwards at the 1999 US Open.
What does she have left? And can Fernandez overcome a dismal record against British players? Remarkably she has a 1-6 record at all levels against British opponents, according to the WTA, and only last month she was beaten by Harriet Dart in Montreal.
This will be the first women's grand slam final between two unseeded players. There have only ever been 21 unseeded women's finalists and seven at the US Open, and if one or both of them freezes in the spotlight it would be excusable, but that prospect appears unlikely given their shared brio and sense of belonging at this level.
Fernandez has been a masterful conductor of the crowd, and has become the third Canadian woman to reach a slam final, after Eugenie Bouchard at Wimbledon in 2014 and Bianca Andreescu at the US Open two years ago. Bouchard was runner-up to Petra Kvitova, while Andreescu beat Serena Williams.
Like Raducanu, her career earnings will be transformed whatever the outcome of the trophy match, with Fernandez having banked $786,772 before this spellbinding run.
RISE OF THE TEENAGER
This will be the fourth US Open women's final in the Open Era to be contest by two teenagers, following on from Steffi Graf's win over Gabriela Sabatini in 1988, which sealed a calendar Grand Slam, the victory by Hingis over Venus Williams in 1997, and Serena's win against Hingis two years later.
Although Raducanu and Fernandez are young, they are put in the shade somewhat by the fact a 16-year-old Hingis played a 17-year-old Venus in that 1997 final.
Overall, it will be the ninth Open Era women's final between two teenagers at the majors, and whoever wins will be the youngest champion since Sharapova's Wimbledon triumph.
Raducanu has come from almost nowhere to become British number one, which will be confirmed in the new WTA rankings next week. Should she win the title, she will move to 24 on the global list, and a defeat would mean she sits at number 32, while Fernandez will be 19th if she carries off the trophy and number 27 should she fall short.
The title would make Fernandez Canada's number one, leapfrogging Andreescu.
At around 16:00 in New York on Saturday, two teenagers will step on court, likely to the wild acclaim they richly deserve. Both might have been able to walk the grounds unnoticed a fortnight ago, but Raducanu and Fernandez are globally recognised now.
At a tournament that has been missing a galaxy of stars – the Williams sisters, Roger Federer and Rafael Nadal to name but four, and we should probably get used to that – these flamboyant greenhorns have shown tennis might just have a future as thrilling as its immediate present.