27-year-old Joshua is on the verge of becoming Britain's richest sportsman if he can maintains his winning performance for the next few years.
Klitschko, who was gracious in defeat and hasn't ruled out a rematch. 'The best man won tonight. We have a (rematch) in contract. But I must analyse what has happened', the legendary Ukrainian said after the bout.
Joshua climb off the canvas and stop Klitschko in the 11th round to claim the biggest victory of his young career.
The fight was by far the biggest the Briton.
US television rights sold for almost £2.4 million, with Showtime and HBO sharing the rights.
German TV RTL has also paid about £4 million to broadcast the event in the country where Ukrainian Klitschko is a star.
Over £1 million was pumped in by sponsors.