Sporting Lisbon midfielder Joao Moutinho has moved to Portuguese rivals FC Porto for a fee of €11million.
The 23-year-old Portugal international had been linked to a number of European clubs and Premier League outfit Everton are known to be long-term admirers.
Moutinho was captain at Sporting but has opted to move on to pastures new, in a deal worth £9.1m.
He has signed a five-year contract at Estadio do Dragao, while defender Nuno Andre Coelho, 24, moves the other way on a deal until 2014.
Moutinho missed out on a place in Carlos Queiroz's Portugal squad for the World Cup this summer, although he featured at Euro 2008.
He will not be playing in next year's UEFA Champions League, however, as Porto only finished third in the Portuguese top-flight last term and will now compete in the Europa League.