AMIR Khan was showered with superlatives by legendary five-time world champion Sugar Ray Leonard after making a successful American television debut at Cardiff's Millennium Stadium.

Khan's 12th professional contest turned out to be one of his most straight-forward as he picked off veteran Doncaster lightweight Steffy Bull at will before stopping him at one minute 45 seconds of round three.

The Olympic silver medallist's bout was broadcast free-to-air in the US by cable giant Home Box Office, and Leonard, watching at ringside, said fans on both sides of the Atlantic would be impressed.

Leonard said: "Amir has amazing attributes. He has hand-speed, power and confidence. He has everything. As long as he is moved on correctly, that kid has the makings of a superstar."

High praise indeed coming from Leonard, but Khan has so far backed up all the prophecies of greatness directed his way and was totally in command.

It was easy to see why it might be too much. Bull, now 24-5-1, had built up his modest record largely on local club shows and had swapped a short-lived retirement and a couple of ringside seats to take the fight.

Khan worked well to the body, winding Bull with a crunching right early in the second as the Doncaster man reverted entirely to survival mode. A jolting right hand to the head in round three weakened his resistance.

Two ripping body shots against the ropes dumped Bull to the canvas. Despite clambering up at the count of eight referee Marcus McDonnell stopped the contest.

Khan will now return in July, likely on the next Joe Calzaghe bill at the former Millennium Dome. The increasingly bullish 20-year-old would love the opportunity to test himself against a major domestic rival.

Khan added: "I'd love to shut their mouths. I believe I would give British champion Jonathan Thaxton a boxing lesson, while Kevin Mitchell and Graham Earl have gone very quiet lately.

"John Murray is not even on my level. Everybody knows who is better.

"He has got a world youth title but he's the one calling me out. It should be the other way round. They're scared and they just see it as a pay-day."

At the top of the bill, Joe Calzaghe made the 20th defence of his WBO belt with a comfortable third-round win over Peter Manfredo which could set up a money-spinning fight against middleweight king Jermaine Taylor - possibly in July.

Enzo Maccarinelli also continued his emergence with an one-sided first round win over Bobby Gunn.