Last night, just three months after starting her professional tennis career, Emma Raducanu won the US Open in straight sets, defeating Leylah Annie Fernandez 6-4, 6-3. Her stunning performance saw her become the first British woman to win a Grand Slam singles in 44 years. Not only that, she's the first ever qualifier to win a Grand Slam tournament - ever.
Today, sports stars, politicians and celebrities are falling over themselves to congratulate the 18-year-old and spell out just how significant her achievement is. (And yes, Piers Morgan has joined in, and no, he's not taken back those Wimbledon comments...)
What are people saying about Emma Raducanu?
The Queen has led the congratulations pouring in for Emma, with the Duchess of Cambridge - a huge tennis fan - finishing her tweet with her initial, a signal that she composed it herself.
Fellow sports stars, past and present, are thrilled by Emma's win, with some praising her resilience after she had to pull out of Wimbledon with breathing difficulties earlier this year.
And Virginia Wade, the last British woman to win a Grand Slam, was in the crowd at New York's Arthur Ashe Stadium to watch it all happen...
... along with the rest of us supporting from our sofas. Channel 4, which aired the match, has confirmed it was must-watch Saturday night viewing for many of us.
The relative ease with which Emma took the title has already seen some draw parallels between her and established sporting greats.
Commentators have been explaining just why her achievement is so major - and why her $2.5 million prize money is worth celebrating, too.
Piers Morgan caused controversy in the wake of Emma's fourth-round Wimbledon exit earlier this year, when he was seen as questioning her mental strength. The columnist remained unrepentant as he congratulated Emma (and suggested she'd taken his advice to 'toughen up').
However, others saw Emma's victory as the perfect riposte to those who had doubted her.
Tennis champ turned pundit John McEnroe has been trending today in the wake of her victory. Some saw his Wimbledon commentary that Emma - then an unknown wildcard - had found the pressure of that tournament 'a bit too much' as unhelpful. So people haven't been slow to point out just how she has risen to this latest occasion.
Some, meanwhile, have argued that Emma's story reflects the importance of Britain's multiculturalism - and have questioned the congratulations rolling in from some politicians, such as Nigel Farage.
As for Emma herself? She's yet to Tweet - she's been a little busy.
READ MORE: The Google Searches For Emma Raducanu Prove How Much Pressure She Was Under