(CNN)The Queen has praised Emma Raducanu's "outstanding" US Open victory on Saturday, calling it a "remarkable achievement."
The 18-year-old from the UK beat fellow teen Leylah Fernandez 6-4, 6-3, to claim her first grand slam title and become the first qualifier in the history of the Open Era to win a major title.
In a letter, Queen Elizabeth II sent her congratulations to the tennis superstar after she clinched the historic grand slam title.
"It is a remarkable achievement at such a young age, and is testament to your hard work and dedication," she wrote. "I have no doubt your outstanding performance, and that of your opponent Leylah Fernandez, will inspire the next generation of tennis players. I send my warmest good wishes to you and your many supporters."
Ranked 150th in the world entering the tournament, Raducanu's fairytale winning run has been the thing of dreams.
The Briton did not drop a set on the way to her maiden major title, showing poise and composure which belied her years on the biggest stage imaginable.
She became the first woman to win a major title in her second grand slam event -- Chris Evert and Venus Williams both got to the final in their third major, but both lost.
Raducanu also became the youngest grand slam singles champion since 17-year-old Maria Sharapova won Wimbledon in 2004.
Her achievement is made even more remarkable when one considers she has yet to win a main draw match on the WTA Tour. Now she is a grand slam winner.
Afterwards, she paid tribute to Fernandez and the tough test she put up in the final, as well as hailing the future of women's tennis.
"I hope we'll play each other in more finals and in more matches on the Tour, on these stages, on such occasions like this on Arthur Ashe," she told CNN Sport's Carolyn Manno.
"I mean it's so enjoyable and for the grand slam final here to have two of us that are young and coming through, it definitely just shows how strong the future of tennis is and hopefully we'll be able to follow in the footsteps of some of the legends that have played and that are playing right now."
'A star is born'
The US Open's first all-teen final since 1999 had the tennis world at a standstill.
And the two youngsters didn't disappoint, displaying flashes of brilliance and resilience as they did battle at Flushing Meadows.
However, despite Fernandez's best efforts, she was unable to stop Raducanu's meteoric rise, becoming the UK's first women's grand slam singles champion in 44 years.
Messages of congratulations poured in for Raducanu in the aftermath alongside the Queen's.
"A star is born," Martina Navratilova, winner of 18 grand slam singles titles, tweeted. "Emma Raducanu makes history and she is just getting started. And will never have to qualify again."
Billie Jean King, 18-time grand slam singles winner,