Manchester United legend George Best says Sir Alex Ferguson has made "a monumental mistake" selling David Beckham to Real Madrid, and describes the deal as a "shambles" for the Old Trafford club.
The England captain will be lining up for the Spanish side next season after the clubs agreed a fee of stg£25million for Beckham.
And Best is in no doubt that Real - and Beckham himself - are the deal's real winners.
He told The Mail on Sunday: "It just makes no sense at all. The whole thing is a shambles and I would be spitting blood if I were a United shareholder. "David's transfer is a bad deal - and one that hands United's best asset to their biggest rivals in Europe.
"They have let him go far too cheaply - he is worth at least stg£35 to stg£40million.
"It's a monumental mistake - and one that Alex Ferguson will come to regret. He has let his emotions rule his head.
"Despite everything, and the way he's been treated, there is only one winner in this whole affair - and I'm glad to say that is David.
"Fergie's dispatching of David will be discussed at every game United play - especially the ones they lose - next season.
"At the same time David will go from strength to strength at Real - it will be the making of him as a true world class player.
Best is convinced Real will come out on top when they meet United again in Champions League action.
The 57-year-old, who enjoyed a celebrity status similar to Beckham during his 1960s heyday, continued: "David is now at the best club in the world.
"Real are in a different class to United - deep down we all know that - and he will be surrounded by the best players in the game. That can only make him a better player.
"He may even wrestle the number seven shirt from Raul. And at some point I'm sure fate will show its sense of humour and pitch United and Real against each other in the Champions League.
"If that happens, Real will surely emerge victorious - and that will really wipe the smile off Fergie's face."