Britain celebrated Emma Raducanu's US Open victory on Sunday, with Queen Elizabeth II leading the festivities as the 18-year-old qualifier made tennis history in New York.

Raducanu beat 19-year-old Canadian Leylah Fernandez 6-4 6-3 to become Britain's first women's Grand Slam singles champion since Virginia Wade at Wimbledon in 1977. She is also the first player to win a major after coming through a qualifying tournament.

"I send my congratulations to you on your success," Queen Elizabeth II said. "It is a remarkable achievement at such a young age, and is testament to your hard work and dedication."

Prime Minister Boris Johnson also congratulated Raducanu for her triumph.

"What a sensational match! Huge congratulations to Emma Raducanu," read a tweet from Boris Johnson's official account.

"You showed extraordinary skill, poise and guts and we are all hugely proud of you."

'New queen of British sport'

Until three months ago, Raducanu never played in a professional tour-level event.

Raducanu's only previous Slam appearance, at Wimbledon in July, ended when she pulled out of her fourth-round match following an anxiety attack.

"Look at that bounce back Emma Raducanu US Open champion, amazing. Congratulations," tweeted England and Manchester United footballer Marcus Rashford, who offered support to the 18-year-old after her Wimbledon exit.

Born in Toronto,  Raducanu moved to London with her parents at age two. Her father is Romanian and her mother is from China.

China also got in on the celebrations. IT firm Tencent published an article featuring photos of Raducanu visiting China as a child.

"An ethnic Chinese won the US Open," it read. "She claimed that her motivation comes from her Chinese mother!"         

Former British number one tennis player Tim Henman said the 18-year-old "will win more of these [Grand Slams]. She is that good."

mvb/jlw (AP, AFP)