© AP Enlarge Luis Collazo has a point deducted for a low blow on Amir Khan, who had three legitimate knockdowns of his own

Amir Khan thought he had a fight against Floyd Mayweather Jr locked up months ago and was bitterly disappointed when Mayweather bypassed him and elected to fight Marcos Maidana instead on Saturday night.

So Khan, a former unified junior welterweight titlist, accepted a spot in the co-feature, moved up to welterweight and scored a clear unanimous decision against former titleholder Luis Collazo at the MGM Grand Garden Arena, hoping his victory was enough of a statement to put himself at the front of the line to face Mayweather in the fall.

Mayweather stays perfect Floyd Mayweather takes a hit from Marcos Maidana © AP Floyd Mayweather maintained his unbeaten record with a majority points verdict over Marcos Maidana, but 'Money' was made to work for his cash by his Argentine opponent.

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"Definitely, people want to see that fight between me and Floyd," Khan said. "He's fighting guys who are strong, but styles make fights, and I believe my style would cause Floyd a lot of trouble."

Although Khan was the clear winner, scoring three knockdowns and outboxing Collazo to win 119-104, 119-104 and 117-106 - ESPN.com also had it 117-106 - the victory was not without some worrisome moments, especially when Collazo really shook him up in the eighth round.

Khan was in command from the outset, showing much faster hands, good movement and power. He hurt Collazo with a pair of right hands early in the second round and also landed a solid left hook.

In the third round, Khan dropped Collazo, catching him with a short right hand during an inside exchange.

Khan sure didn't look like a fighter who had been out of the ring for 13 months, a layoff caused mainly because he thought he had the Mayweather fight and pulled out of the late stages of negotiations for a fight with then-welterweight titleist Devon Alexander in December.

"One thing about [trainer] Virgil Hunter is it's the first time we ever spent a long time together," Khan said. "He taught me some good things and I put them together tonight. [Collazo] was very awkward.

"I think it was great to have that layoff. I needed a break from boxing but at the same time I needed to work on some things."

Collazo put himself in an even deeper hole in the eighth round when he landed a very low blow and referee Vic Drakulich, who warned Collazo earlier, took away a point.

Moments later, Collazo landed his best punch of the fight, rocking Khan with a left hand and making his legs turn to jelly. Khan was still hurt when Drakulich took a point from him later in the round for holding.

Khan (29-3, 19 KOs) seemed to be fading in the ninth. He was trying to stay away from Collazo (35-6, 18 KOs), who was aggressive and trying to walk him down, knowing it might only take one hard shot to damage Khan, whose poor chin has been well-established.

But Khan came back strong in the 10th round, dropping Collazo twice late in the round, first with a big right hand on the chin and then moments later on a combination late in the round.

"I had to hang in there," said Collazo, who landed the big fight with Khan by knocking out former titleist Victor Ortiz by second-round knockout in January. "That's how we do it. I hurt my left knuckle. His style is tough. He kept grabbing me. Things happen."

In the opening moments of the 12th round, Collazo landed a brutal low blow that sent Khan to the mat and Drakulich gave him time to recover, but Khan got himself together and cruised to the bell.

This article originally appeared on ESPN.com

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