Porto have signed Mexico international full-back Miguel Layun from Premier League newcomers Watford.
The deal was confirmed late on Monday, though details of the transfer were not disclosed.
Layun follows in the footsteps of Mexico team-mate Jesus Corona, who joined the Portuguese giants from FC Twente on the same day.
The 27-year-old Layun appeared in three of Watford's four Premier League matches this term, scoring in their 2-2 draw with Everton on the opening day.
Layun arrived at Watford from CONCACAF Champions League winners America in January this year, signing a four-and-a-half year deal.
He played 17 league games in his first season as Watford gained promotion to the Premier League.
‘Newcastle’s board said I was over the hill, so I left and played 108 consecutive games and won the European Cup – not a bad way to answer that accusation!’: Ex-Magpies defender reflects on career highlight after proving former side wrong
‘Parma viewed him as the perfect replacement for Adrian Mutu, who’d left to sign for Chelsea. But Manchester United’s interest was much more concrete’: Cristiano Ronaldo's 2003 transfer details revealed by former Sporting director of football
