The 19-year-old dropped her racket after hitting a blistering forehand return winner on match point to seal victory at Arthur Ashe Stadium and collapsed on her back after embracing her defeated opponent.
Canadian teenager Bianca Andreescu claimed her first Grand Slam title in a hard-hitting and nerve-jangling 6-3 7-5 win over Serena Williams on Saturday that put the brakes on the American's bid to equal the all-time record.
Andreescu matched Williams' power throughout the slugfest and kept her composure under intense pressure to fend off a late comeback from the six-times US Open champion.
The 19-year-old dropped her racket after hitting a blistering forehand return winner on match point to seal victory at Arthur Ashe Stadium and collapsed on her back after embracing her defeated opponent.
So new is Bianca Andreescu, who wasn't even born when Williams won her maiden Grand Slam in 1999, to the stage that after beating Serena Williams to win the US Open on Saturday, a tournament official had to show her which side of the trophy was the front.
"It's so hard to explain (what the win means) in words," Andreescu said on-court.
"I'm just beyond grateful and truly blessed. I've worked really, really hard for this moment and I can't complain. This year has been a dream come true," she added before collecting her $3.85 million winner's cheque.
"And now to be able to play on this stage against Serena, a true legend of the sport is amazing."
Andreescu, the first Canadian to win a major in the professional era, prevented Williams from equalling Margaret Court's record of 24 Grand Slam singles titles.
Williams, who has been denied the milestone in four slam finals since claiming her last major title at the Australian Open in 2017, was gracious in defeat.
"Bianca played an unbelievable match," she said.
"Congratulations, I'm so proud and happy for you. I wish I could have played better."
The fearless Andreescu pressured Williams from the outset, electing to receive after winning the coin toss and immediately breaking her childhood idol.
Shouting "come on" after winning key points, Andreescu's vicious forehands kept Williams on the back foot while costly errors, including a double fault on set point in the first, put the American in an early hole.
With her back against the wall trailing 5-1 and facing championship point, Williams mounted a spirited comeback to draw level at 5-5, leading to deafening roars from the packed crowd in the biggest tennis stadium in the world.
Yet Andreescu, who covered her ears at times, regained her steely composure to cross the finish line.
Andreescu's Road to Final:
First round: Katie Volynets (US) 6-2 6-4
Second round: Kirsten Flipkens (Belgium) 6-3 7-5
Third round: 19-Caroline Wozniacki (Denmark) 6-4 6-4
Fourth round: Taylor Townsend (US) 6-1 4-6 6-2
Quarter-finals: 25-Elise Mertens (Belgium) 3-6 6-2 6-3
Semi-finals: 13-Belinda Bencic (Switzerland) 7-6(3) 7-5
Final: 8-Serena Williams (US) 6-3 7-5
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