Leylah Fernandez continued her rampage in New York by defeating Aryna Sabalenka to reach the US Open final, where she will face fellow teenager Emma Raducanu, who in turn dismantled 17th seed Maria Sakkari.
The Canadian, who turned 19 on Monday, stunned world number two Sabalenka in a dramatic three-set semi-final.
Fernandez, ranked 73 in the world, has laid waste to a who’s who of women’s tennis this fortnight.
And she added Sabalenka to the scalps of defending champion Naomi Osaka, 2016 winner Angelique Kerber and fifth seed Elina Svitolina with a 7-6 (3) 6-4 4-6 victory in two hours and 21 minutes.
Fernandez had the crowd firmly behind her and the roar inside Arthur Ashe Stadium as Sabalenka sent the final point long could probably be heard in her hometown in Quebec, a neighbour of New York State.
She said on court: “I have no idea how I won. I want to say thanks to the New York crowd, they helped me today and never gave up. Thanks to them I was able to win.
“I just wanted to be in the final and I fought for every point. I don’t know how I got that last point in but I’m glad it was.”
Second seed Sabalenka came roaring out of the blocks, playing some near-perfect power tennis as she hit nine winners and no unforced errors to lead 3-0.
But two double faults from the Belarusian helped Fernandez break back and the youngster saved a set point as she clung on for a tie-break.
With errors creeping in from both players it was Sabalenka who tightened up the most, a horrid overhead miss and another double fault allowing Fernandez to snatch the opening set.
It was a similar story at the start of the second as Sabalenka broke to love but Fernandez, eating up her opponent’s increasingly frequent second serve, levelled for 2-2.
Sabalenka took her anger out on her racquet during the changeover, earning herself a warning from the umpire.
But, frustration vented, the Wimbledon semi-finalist secured another break for 5-4 and served out to love to take the match to a deciding set.
The pair exchanged breaks midway through the third but could not be separated until Sabalenka wilted on serve, and Fernandez sank to her knees after completing another memorable victory on her remarkable journey to a first grand slam final.
Later on Thursday in the other semi-final Raducanu defeated Greece’s Sakkari 6-1 6-4.
With the win the 18-year-old Briton became the first qualifier – male or female – to ever reach a grand slam final.
Raducanu saved seven break points in her first two service games while breaking 26-year-old Sakkari to 15 to secure a 3-0 lead.
The world number 18 then dropped serve again and in the blink of an eye the first set had run away from her.
An early break in the second kept Sakkari at bay and only an extraordinary rally at break point prevented Raducanu from taking a 5-2 lead. No matter.
Two service holds and a delicious volley on match point later and Raducanu had completed the latest stride in her improbable march towards sporting immortality.
“Honestly the time here in New York has gone so fast. I’ve just been taking care of each day and three weeks later I’m in final. I can’t actually believe it,” Raducanu said on court.
“Since I’ve been here from the first round of the quallies I’ve had unbelievable support.”
As for her chances in the final? “Is there any expectation? I’m a qualifier so technically there’s no pressure on me,” she added.