However, those who paid to watch instead on Primetime TV will have been left as disappointed as those in attendance at the MEN Arena as Khan was embroiled in a scrappy encounter for five and a half rounds before a clash of heads forced his previously unbeaten but unfancied opponent out.

The fight therefore went to the scorecards, with Khan's superiority showing as he claimed every round for a comprehensive but unsatisfactory victory.

Ulster southpaw McCloskey, 31, came into the fight with a 22-fight unbeaten record featuring 12 early wins but was given little chance of victory by bookmakers.

Indeed, the humble challenger insisted this week he would keep working alongside his wife at a local shop in his native Dungiven, even if he succeeded in dethroning Khan.

The 24-year-old champion (24-1, 17KOs) was also looking ahead to the future in the build-up, admitting he already had one eye on a summer unification showdown with WBC/WBO champion Timothy Bradley.

But he could not afford to take his eye off the ball at the scene of his only career defeat here, where Breidis Prescott demolished him inside a minute in 2008.

While much was made of what Khan claimed was a lack of television support in Britain last week, he was backed numerically by a decent crowd in Manchester of around 18,000. That also consisted of well in excess of 7,000 McCloskey fans, though, who often drowned out their rivals.

Both were determined to put on a show to repay that faith although the opener was tentative. Khan pressed but found his fast hands matched by McCloskey's quick reflexes, though the champion did land two decent body shots and a reaching right.

Khan was more assured in the second as he landed in threes and fours, though McCloskey held ring centre and closed the round with a solid southpaw left.

McCloskey was at least making a scrap of it and had Khan on the back foot at times, catching him nicely on the chin with another winging left in the third.

The challenger slipped in the next session after a coming together but the action was more of the same until Khan landed a hurtful, sharp right hand. McCloskey fired back immediately but received a left hook to the head for his trouble.

Khan dug McCloskey with left hooks early in the fifth as the challenger continued to load up left hands, only to be caught with a hard right to the chin.

McCloskey's awkward southpaw style was making the home fighter's life difficult but when Khan landed a hurtful flurry it clearly took its toll in the sixth.

McCloskey recovered well but moments later the fight was over, an accidental clash of heads leaving the challenger cut over the left eye. Referee Luis Pabon summoned the doctor, who studied the wound closely before advising the official to call a halt to proceedings immediately.

And it was Khan who rode out victoriously on the scorecards, with all three judges having awarded him every round with scores of 60-54.

McCloskey's fans and team were fuming and Khan, while delighted, clearly felt for his opponent.

"I'm sorry it had to end that way," he told McCloskey before shaking hands with the loser.

McCloskey stopped short of accusing Khan of dirty tactics - indeed, the champion seemed blameless - but the Ulsterman was clearly unhappy.

"The way the doctor put it to me, I thought I was badly cut," he said. "He told me it was really bad."

Asked whether he thought Khan was being careless with his head, McCloskey said: "How did I get the cut? I wouldn't say he did it intentionally but it was a clash of heads."

On the undercard, Leicester binman Rendall Munroe made a winning return following his unsuccessful world title challenge last year with a unanimous decision win over Andrei Isaeu.

Earlier, Craig Watson lost his British welterweight title to Lee Purdy after being dropped and stopped in round five.