Middlesbrough have completed the signing of Sunderland midfielder Julio Arca for a fee of £1.75m.
Arca has swapped Wearside for Teesside
The 25-year-old Argentine, who has been with the Black Cats for six years, has agreed a five-year deal with Boro.
Arca said: "The move is for football reasons more than anything. I want to play in the Premiership and this club helps me do that.
"I also want to get into the national team and playing for this club will go a long way to make that happen."
Arca added: "Last season was hard for everyone and it was very disappointing to go out of the Premiership.
"I spent several years at Sunderland and was very happy there, but you have to do what is right for your career."
Arca, who was also interesting Spanish side Espanyol, joined Sunderland for £3.5m from Argentinos Juniors in 2000 and became a huge favourite on Wearside.
But he was given permission to talk to Boro by new Sunderland boss Niall Quinn.
He added: "When Middlesbrough came in, obviously I wanted to listen. This is a big club and these opportunities don't come along every day."
He becomes the first senior signing for the Teesside club under new manager Gareth Southgate.
Southgate said: "As soon as I discovered that Julio was available it didn't take us long to make a decision.
He is also a player who excites the fans and can make us a better club
"In the games against Boro last year, Julio showed us exactly what he can do so I am delighted to be able to bring such a top-quality player to the club.
"The thing about Julio is that he symbolises the way I want to play. I want a team that thinks and that attacks, and Julio has shown me on the occasions that I have played against him that he is an attacking player.
"He can play in midfield or he can play at left-back, and I want my full-backs to push forward this season. Julio can do that.
"He has been very loyal to Sunderland for the last five years and I know that he has the right kind of character that I want to bring into the dressing room.
"He is also a player who excites the fans and can make us a better club."
It caps a promising week for Southgate, who has seen Chris Riggott and Andrew Taylor sign new deals.
Arca was in the final year of his contract and Quinn admitted he had a clause in his deal allowing him to talk to Premiership clubs following Sunderland's relegation.
Quinn had tried to persuade Arca to stay with the club, and promised to match Boro's offer.
But the lure of Premiership football, while staying in the north-east, appears to have been too much for the former Argentina Under-21 international.
Quinn said earlier: "I'm not cross - he has already stayed once after this club went down - but I am disappointed as he is a terrific guy and a smashing player."
Arca remained loyal to the club despite their previous relegation to the Championship in 2003.
And he even signed a new two-year extension in November 2004, despite interest from the likes of Newcastle, Celtic and Italian side Fiorentina.
He made 177 appearances for the club, scoring 23 goals.