Gedson Fernandes has joined Tottenham on an 18-month loan from Benfica.
The deal comes with an option to buy the 21-year-old midfielder for £42.76m (€50m).
Benfica agreed deals with Tottenham and West Ham but Fernandes has opted to sign for Spurs, who are managed by fellow Portuguese Jose Mourinho.
Chelsea offered an initial loan deal with an obligation to buy for £55m should Fernandes play at least 50 per cent of games over the 18-month period, while West Ham are thought to have made a similar offer with an obligation to buy for £33m, with a lower percentage of appearances triggering the purchase.
Lyon and AC Milan also made formal offers but Fernandes' preference was a move to the Premier League.
Tottenham have been keen to bolster their midfield following an injury to Moussa Sissoko, who has been sidelined for three months after undergoing surgery to the medial collateral ligament in his right knee. He is set to miss three months.
Fernandes, who has two caps for Portugal, has made 53 appearances in all competitions for Benfica, scoring three times. He will wear the No 30 shirt for Spurs.
Why Fernandes' rise stalled at Benfica
Filipe Dias, editor in chief of Portuguese newspaper O Jogo, joined the Transfer Talk podcast to explain why Benfica were ready to let one of their most promising young players leave the club this month.
"It is a mutual thing to part ways, at least for the time being. Gedson wants and needs playing time really badly," Dias said.
"His transition from the youth system to the main [Benfica] squad appeared to be smooth at first but that happened under the previous manager Rui Vitoria.
What Gedson Fernandes brings to Spurs
The lowdown on the 21-year-old midfielder following his loan move from Benfica
"With the current coach, Bruno Lage, Gedson was gradually dropped from the first team and became second choice.
"Benfica want a good deal for a player whose rise has stalled and Gedson needs to regain his confidence. That can only happen by playing. He needs a manager who believes in him so he can find his feet.
"We are talking about a player who has great passing ability, exquisite reading of the game, power, courage under pressure, but I think he is still a little bit immature when it comes to his decisions on the pitch.
"His main weakness, in my assessment, lies in his positioning. He is a central midfielder but he has not found his position specifically. Sometimes he plays in a more attacking role, while other times he plays more defensively but he has not stood his ground in one position only and I think he needs this badly.
"He also needs a manager who will be patient with him."
How to follow the January transfer window with Sky Sports
Sky Sports will bring you the very latest news from the January transfer market with the return of three shows.
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