Emma Raducanu completed one of the most astonishing stories in tennis history as the British teenager captured the US Open title with victory over Canada's Leylah Fernandez in New York.

In an all-teenage final at Flushing Meadows, Raducanu ran out a straight-sets winner 6-4 6-3 to become the first British female Grand Slam singles champion in 44 years.

Appearing in just her second Grand Slam, the teenage star also becomes the first qualifier – male or female – to go all the way to the title at a major tournament in the Open Era. 

Raducanu and Fernandez, 19, had defied expectations to come this far in New York, having started the tournament unseeded.

Fernandez saw off defending champion Naomi Osaka, fifth seed Elina Svitolina and second seed Aryna Sabalenka on her way to a maiden appearance in a major final.

Raducanu, meanwhile, had not dropped a single set on her route to Saturday's showdown – becoming the first star in the Open Era to emerge from qualifying and set up a shot at a Grand Slam title.

The Brit continued that form to boss the final at Arthur Ashe Stadium, also overcoming some late drama as she cut her leg while serving for the match.

As Raducanu called a medical time-out, Fernandez appeared angry when the Canadian had a breakpoint and a chance to wrestle back the initiative. Still, the Brit was patched up and went on to save another break point before seeing the match – and the championship – with an ace.

As the records tumbled with her feat in New York, Raducanu also became the youngest Grand Slam queen since Russia's Maria Sharapova won Wimbledon as a 17-year-old back in 2004. 

That victory propelled Sharapova to global stardom – as well as a further four Grand Slam titles – and similar might now be expected from Raducanu. 

Given Raducanu's rise from an outsider to a Grand Slam queen, many hailed her New York fairytale as among the most incredible stories that tennis – and perhaps even sport as a whole – has ever witnessed. 

Raducanu will pocket $2.5 million in prize money for her title win in New York, capping a life-changing few weeks that even she has admitted she did not see coming. 

The young star, who was born in Canada to a Chinese mother and Romanian father but moved to the UK at the age of two, was taking her A-Level school exams just a few months ago but has now become a national icon in Britain and a heroine far beyond her home country.

Raducanu first emerged into the broader national conscience at Wimbledon in her maiden Grand Slam appearance in the summer, but on that occasion was forced to retire from her fourth-round match due to breathing problems.

Some in the media – including US tennis icon John McEnroe and UK TV personality Piers Morgan – appeared to question Raducanu's resilience due to her withdrawal. Still, she has bounced back in a style that few would have expected.