The sensational swoop was made possible after the Abu Dhabi United Group made a significant investment in the Blues, with the UAE-based group set to complete a takeover from current City owner Thaksin Shinawatra.
Ctiy then launched an audacious £30m-plus bid for United target Dimitar Berbatov, followed by offers for Spanish star David Villa and German striker Mario Gomez.
And although Berbatov later completed a move to Old Trafford, news filtered through at around 10pm that Real Madrid had agreed a fee with City for Robinho.
"I am absolutely delighted to get the opportunity to work with such an incredible talent like Robinho," manager Mark Hughes told the City website.
"I have said that in order to compete with the best teams in the Premier League we have to be in the market for players of this calibre, and Robinho is undoubtedly one of the best players in the world.
"I am really looking forward to introducing him to the rest of the squad, and to the City fans at the earliest opportunity. This is a real statement of intent as to the ambitions of Manchester City Football Club."
The Robinho deal follows the surprise return of Shaun Wright-Phillips from Chelsea last week.
The City fans now face the mouth-watering prospect of SWP and Robinho's first game together being at home to, yes, you've guessed it.. Chelsea!!