Britain's Oliver Golding won the US Open boys' title with victory over junior world number one Jiri Vesely.
The 17-year-old from London came from a set down to triumph 5-7 6-3 6-4 against the top seed from the Czech Republic.
It is the first time a British player has lifted a boys' Grand Slam title since Andy Murray won at Flushing Meadows in 2004.
Golding, who partnered Vesely to Youth Olympic Gold in 2010, reached the boys' semi-finals at Wimbledon last year.
The 13th seed fought back well after dropping the first set of Sunday's final and overcame a rain delay at the start of the decider to seal victory after two hours and 18 minutes.
Vesely, the Australian Open junior champion, saw off four break points at 5-4 down in the first set before breaking in game 11 and, after a brief rain interruption, served out for the set.
Golding stuck to his aggressive game plan in the second set and it paid off when he broke for 3-1, going on to convert his fifth set point to level.
The rain returned after just three points of the second set, but on the resumption Golding grabbed the decisive break in game seven and he sealed victory with a backhand.
"I played a really good match," Golding told BBC Radio 5 live. "I've had some tough matches all week but that was the hardest of all of them.
"He had a lot of break points and I managed to hold on. I was a bit upset I didn't win the first set but I held it together and played really well after that. It was kind of surreal at the end, I was playing so well."
Golding now plans to continue the transition to the senior game by playing on the ITF Futures circuit, although he might play some more junior events if he can finish the year as junior world number one.
Golding joins the likes of Pat Cash, Stefan Edberg, Andy Roddick, Jo-Wilfried Tsonga, Richard Gasquet, David Nalbandian and Andy Murray as a US Open boys' champion.
And he added that he had spoken to British number one Murray during the fortnight at Flushing Meadows.
"I've seen him around a couple of times and we wished each other luck," said Golding. "Unfortunately he came up short here but I'm sure he'll get a Grand Slam title soon."