Adnan Januzaj has signed a five-year contract with Manchester United, the Barclays Premier League champions have confirmed.
The 18-year-old winger has been one of the breakthrough acts of the season and made his name with a match-winning two-goal show against Sunderland in United's last fixture before the international break.
That sparked a debate about his international eligibility, with England keen on joining the list of countries he is available to play for.
United boss David Moyes told the club's official website: "I'm delighted that Adnan has committed his future to United
"He is an outstanding talent and has impressed me consistently since I came to United in July.
"His balance, poise and ability to beat players is truly exceptional for a boy of his age.
“It's great that he recognises that this club, with its tradition for developing young players and giving them a chance on the biggest stage, is the best place for him to be."
Moyes had said on Friday that he was hopeful Januzaj would extend the deal which expired at the end of the current campaign, although club officials had described the negotiations as "complicated".
For Januzaj, though, who joined United from Anderlecht in 2011, the choice was an easy one.
"Since arriving here I have always felt like this was the right club for me" - Adnan Januzaj
"It's a great thrill to be able to sign for Manchester United. Since arriving here I have always felt like this was the right club for me," he said.
"This season has been great for me - going on the pre-season tour, making my debut in the Community Shield win at Wembley and then breaking into the team at Sunderland - it's like a dream. I want to work hard now and establish myself as a Manchester United player."
A deal through to 2018 will also complete five years in England after the age of 18 for Januzaj, meaning he would have served the time needed to become available for England on residency grounds, should he so wish.
When it was revealed the English Football Association had asked after Januzaj in the wake of the Sunderland game, it kicked off a heated debate over eligibility.
Arsenal and England midfielder Jack Wilshere found himself at the heart of it, saying: "The only people who should play for England are English people.
"If you live in England for five years it doesn't make you English."
Januzaj was born in Brussels and therefore eligible for Belgium but is also available to play for Albania, Kosovo, Serbia and Turkey.