'Remarkable achievement': Queen Elizabeth leads explosion of British joy at Raducanu's stunning Slam win
"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."
Britain's Emma Raducanu beat Canadian Leylah Fernandez 6-4 6-3 in the battle of the teens to be crowned US Open champion.
She is the first qualifier to win a Grand Slam title and the first British woman to hoist a major trophy since Virginia Wade triumphed at Wimbledon in 1977.
Here are some reactions to the win:
Britain's Queen Elizabeth, In Message To Raducanu
"I send my congratulations to you on your success in winning the United States Open Tennis Championships. It is a remarkable achievement at such a young age, and is testament to your hard work and dedication.
"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."
The Duke and Duchess of Cambridge
"Huge congratulations @EmmaRaducanu on your stunning performances and historic Grand Slam victory! Incredible – we are all so proud of you.
@LeylahFernandez well done on your amazing achievements at this year's US Open, it's been a pleasure to watch."
The Prince of Wales and the Duchess of Cornwall
"Well done to @LeylahFernandez today too. An outstanding match between two inspiring young women - we can't wait to see where you go next."
Boris Johnson, Prime Minister of the United Kingdom
"What a sensational match! Huge congratulations to @EmmaRaducanu
"You showed extraordinary skill, poise and guts and we are all hugely proud of you."
Nicola Sturgeon, First Minister of Scotland
"I suspect tonight is one of these sporting occasions that will be talked about for decades to come. Two great players who will no doubt dominate women's tennis for years to come."
18-time Grand Slam Singles Winner Martina Navratilova
"A star is born- Emma Raducanu makes history - never has a qualifier won a major - men or women - and she is just getting started. And will never have to qualify again.
"Leylah Fernandez will be back -both are champions but Emma has the trophy- well done!!!"
12-time Grand Slam Singles Winner Billie Jean King
"What a terrific display of competition & maturity from two exceptional players. It is wonderful to see this generation living our dream. I can't remember a #USOpen with better crowd support. Thank you, NY, the greatest fans in the world.
"And congratulations, Emma!"
11-time Grand Slam Winner Rod Laver
"Well done Emma Raducanu, the first of many duels with Leylah Fernandez. I've no doubt many more majors await for both of you. Another historic moment at the #USOpen - congratulations."
Former England Footballer Gary Lineker
"What a performance, what a triumph, what an amazing young woman. Congratulations @EmmaRaducanu on a truly staggering achievement. US Open winner at 18 without losing a set. Extraordinarily fabulous."
7-time Grand Slam Winner Mats Wilander on Eurosport
"I have never heard a crowd in Grand Slam tennis being this loud, this appreciative of the players and the player responding. This was an epic of the US Open. It was a great comeback of the U.S. Open, it was just an amazing two weeks."
Alex Corretja, Former World No. 2 and Eurosport Tennis Expert
"I don't think we will see this again from a player from qualifiers, not losing games, sets, that's something superior Emma did very well. It's such great news for tennis, women's tennis and sports in general."
British Actor Stephen Fry
"What a glorious day for two remarkable young women. Yes, it may be 'only' sport, but in that 'only' there can be found so much of human joy, despair, glory, disappointment, wonder and hope. A brief flicker of light in a dark world. #EmmaRaducanu #LeylahFernandez #USOpenFinal"