AMIR Khan knows tonight's fight with Luis Collazo could be his last chance of earning a bout with Floyd Mayweather.

Khan fights at Las Vegas’ famous MGM Grand arena for the first time when he takes on Collazo for the WBC silver welterweight belt, on the undercard of Mayweather’s contest with Marcos Maidana.

The Bolton boxer has been aiming towards a fight with Mayweather since the start of the decade, but suffered setbacks with defeats to Lamont Peterson and Danny Garcia.

Hopes that the Mayweather bout would happen early this year were then dashed when the pound-for-pound number one instead chose to face Maidana.

Khan is still in contention to fight Mayweather, possibly as soon as September.

But he admits he needs to win in style against Collazo – knowing he may not get another chance to book a fight with Mayweather, who is now 37 and starting to hint at retirement.

“I see every fight as the last chance, if I mess up I’ll never be where I need to be,” said Khan.

“I can’t make any mistakes, especially now I’m getting older.

“I know I’m still 27 but I’ve been in the professional game such a long time and I can’t afford to make any mistakes.

“It’s all about winning and winning in style.

“I want to put a good performance in and then the fans will say we want to see Khan v Mayweather.”

Mayweather’s adviser Leonard Ellerbe yesterday appeared to signal that defeat would end Khan’s hopes of that fight, adding that ‘winning solves everything’ for the Boltonian.

Even if Khan beats Collazo, though, there could still be complications around scheduling a fight with Mayweather for September.

Mayweather is due to fight then, but Khan thinks he would not be ready after fasting for the Muslim holy month of Ramadan.

“Ramadan is right in the middle of the year,” Khan said. “I can’t take the fight in September because I need a couple of months to work on my strength and conditioning.”

But his promoter, Richard Schaefer, is still keen for any potential Mayweather fight to happen then.

Schaefer said: “I don't know if there is a way for Amir to train during Ramadan so the fight can still happen in September.

“These are discussions we would have to have.

“But Amir has to be smart against Collazo. In the welterweight division only one guy can beat Amir Khan and that is Amir Khan.”