Monaco have completed a reported £50m deal for Atletico Madrid striker Radamel Falcao.
The Colombian (27), who scored 32 goals this season, had also been linked with Chelsea and Manchester City.
He has signed a five-year contract with a club that is being bankrolled by Russian billionaire Dmity Rybolovlev.
“We are proud to have secured one of the best players in the world and confident he will help Monaco regain its rightful status,” said Rybolovlev.
“We are absolutely delighted that Radamel Falcao has accepted the challenge of coming to play for AS Monaco.”
Monaco have embarked on an ambitious spending spree after winning the French second division under former Chelsea boss Claudio Ranieri.
They have already bought Porto midfielders Joao Moutinho (26), and James Rodriguez (21), in a £60m double deal and signed defender Ricardo Carvalho (35), on a free transfer from Real Madrid.
However, Vasilyev has dismissed reports his club are interested in Manchester City’s Carlos Tevez, insisting: “Many newspapers talk about it but this issue has never been discussed.”