Chelsea have completed the signing of Anderlecht striker Romelu Lukaku.
The two clubs reached agreement on a fee, reported to be around £20m, on 6 August, but the details of the move were finalised after he played for Belgium earlier this week.
The 18-year-old is available for selection for the Blues' match at home against West Brom on Saturday.
"I dreamed to play here since I was 10 years old. It was just what I was searching for," he said.
"I used to watch Jimmy Floyd Hasselbaink scoring goals and remember one against Manchester United, the volley at Old Trafford, and I decided I wanted to support this team.
"It's amazing to arrive here in a big club with big ambition. It was just what I was searching for."
Lukaku became a household name in Belgium when he was top scorer in the domestic league in the 2009-2010 season, aged 16.
He scored 16 goals in 37 league goals last season and scored his first international goals in a 2-0 win over Russia in November.
Lukaku, whose father Roger played international football for Zaire, is a Chelsea supporter and predicted he would play for the club on a school visit to Stamford Bridge two years ago.
"I just want to learn and train as much as possible to improve myself and show the coach that when he needs me I am ready," he added.
"Then I hope to make minutes for the team and be helpful for the team, because the team is the most important thing."
His arrival adds further firepower to a Chelsea squad that already includes Fernando Torres, Didier Drogba, Nicolas Anelka, Daniel Sturridge and Salomon Kalou.
"He's an interesting young prospect," said boss Andre Villas-Boas after Chelsea's pre-season friendly win over Rangers on 6 August.
"The situation is now that we have to position ourselves to maybe get this kind of talent."
Manager Herman van Holsbeeck had previously said it was "a shame" that Anderlecht could not retain Lukaku, but admitted it was "a win-win situation for the player and the club".