Before Anthony Joshua met Charles Martin in the ring at The O2 , Greenwich, Sky Sports ran endless footage of the two discussing the fight, assessing the odds, ruminating on Charles’ southpaw stance and Joshua’s relative greenness.

After the fight, which lasted less than two rounds, all that was needed to answer all those questions was a second of footage when Joshua saw an opening and laid out Martin with the speed of a space rocket and the power of a piston.

Martin will certainly be replaying that moment over and over, and wincing every time. For Joshua, he reacted like it was all in a day’s work. He partied till the early hours but went to the gym on Sunday.

Former Chelsea boss Jose Mourinho paid a visit to the Brit boxer in his dressing at The O2 – perhaps to pass on the title of the “Special One” to the new IBF world heavyweight champion.

Joshua said: “Every fight gets better and better. It’s not just about power. It’s about speed and precision. Martin was big and brave enough to bring his title to the UK. Respect to him. I ain’t gonna get too carried away.”

Charles Martin had talked a good fight but never got started. Joshua bossed the first round, then come the piledriver in the second. Martin beat the count but not the inevitable and he was down and out seconds later.

This was his 16th professional fight and he joins an illustrious group of elite boxers who have held pro heavyweight world titles while still a reigning Olympic champion. Leon Spinks is another and the third is a certain Muhammad Ali whose presence is contained in The O2’s exhibition dedicated to the greatest of all time .

Watching the fight in Greenwich was David Haye. He’ll be back at the arena in May for Haye Day II but his dream bout is Joshua.

Speaking a day later at Canary Wharf, Joshua was asked whether a Joshua/Haye fight was in the offing. “Potentially, potentially,” replied the champ, being polite. He hedged even that lukewarm response with caveats about his management and his desire to fight someone “who presents a threat”.

Not David Haye then, one sense. Not yet anyway.

More likely is a clash with Tyson Fury, another British world heavyweight champ, in a unification fight. Fury dethroned Wladimir Klitschko in November and fights him again on July 9 but the Joshua v Fury match-up is the one that the punters want to see.