Hatton became the first fighter to floor the experienced Castillo

Former WBC super middleweight champion Richie Woodhall described Hatton's performance as "phenomenal".

While former WBA featherweight champion Barry McGuigan said Hatton could now choose his next opponent from a position of considerable strength.

"The likelihood is a fight against Shane Mosley - that is a fight that can be made very quickly," McGuigan said.

Interview: World champion Ricky Hatton

Other names being mentioned in the immediate aftermath of the fight in Las Vegas were Oscar de la Hoya, Miguel Cotto and Floyd Mayweather.

In extending his record to a perfect 43 victories, the Mancunian became the first boxer to floor Castillo in his 17-year career.

I wouldn't be surprised to hear that Castillo has broken a rib Richie Woodhall

"To put a Mexican on the floor like that and to make him quit, that is a phenomenal performance," said Woodhall.

Hatton had Castillo in trouble from the first round but had to overcome some roughhouse tactics from an opponent who had a point deducted for low blows.

Woodhall had nothing but praise for Hatton's ability to dominate the fight from the inside before applying the coup de grace with a stunning body shot in the fourth round.

"I wouldn't be surprised to pick up a paper and hear that Castillo has broken a rib there, it was a peach of a punch," he said.

"He knew he had to impress. I said before it would be the ultimate victory if he was to beat a Mexican by out-powering him on the inside because Castillo is an expert inside fighter. But he was just out-muscled.

"Castillo landed a couple of low blows and the referee was right to jump in.

"This was Castillo's 64th fight and he has been in the game 17 years, but he didn't want to get up from that punch. He is a very experienced man, but the power told in the end from Hatton."

And veteran promoter Bob Arum had only one word to describe the English fighter's display at the Thomas & Mack Center: "Perfect."