Chelsea have confirmed that Diego Costa has completed his £32 million move from Atletico Madrid.
Costa has signed a five year contract, and will join up the his new team-mates next week for Chelsea's European training camp.
The clubs had already agreed the fee in the beginning of July, but Costa has been on holiday since Spain's early World Cup elimination.
"I am very happy to sign for Chelsea," Costa told Chelsea's official website.
"Everybody knows it is a big club in a very competitive league, and I am very excited to get started in England with a fantastic coach and team-mates. Having played against Chelsea last season I know the high quality of the squad I am joining.
"I would like to thank everybody at Atletico who made me into the player I am, it was an incredible time for me, but now I am starting a new adventure and I hope to win many trophies with Chelsea."
He told GloboEsporte.com that he is looking forward to fighting Fernando Torres for the main striker’s role at Chelsea and believes he will make an immediate impact in the Premier League.
"It's always good to have competition. The important thing for a big club is having great players," he said.
"Torres is a great player, I know I will fight hard to be among the holders and I like it. So I think it will be a clean and healthy competition."
"I am hopeful for what is happening in my life and I will adapt well.
"I have wanted to play in the Premier League for a long time and I think it will be a very good and fast adaptation.
"I do not think there will be many changes to the style of play. Chelsea are a great team and the Premier League is good to play in."
Costa has scored 36 goals for Atletico last season, helping them to lift the La Liga trophy and finishing runner-up in the Champions League.
However, he failed to make an impact at the World Cup after choosing Spain ahead of his native Brazil.
Do you think Diego Costa will continue his goal-scoring record at Chelsea or struggle like during the World Cup? Have your say in the comment section below.