Amir Khan catches Luis Collazo with a right cross en route to outpointing the veteran on May 3, 2014, in Las Vegas, Nev. Photo by Harry How/Getty Images.

LAS VEGAS – If it was an audition for a fight with Floyd Mayweather Jr. in September, Amir Khan should be getting a callback soon. Khan dropped Luis Collazo three times – once in the fourth and twice in the 10^th – on the way to a lopsided 12-round decision at the MGM Grand Garden Arena on Saturday night.

It was a superb performance by Khan against a tough veteran in Collazo (35-6, 18 knockouts), who had lost some narrow and controversial decisions to Ricky Hatton and Andre Berto. It was the best anyone had done against Collazo since Shane Mosley defeated him in a 12 round decision in 2007. The margins on the scorecards were as wide as they were in that fight as they were in Khan’s victory on Saturday night. Judges Cathy Leonard had it 119-104 and Adalaide Byrd had it 119-104 and judge Jerry Roth had it 117-106. Both fighters had points deducted in the fight.

Khan said it was a spectacular audition for a match against Mayweather.

“Definitely. The crowd knows it,” he said. “Styles makes fight and I really believe my style will make for a tough fight against Floyd.”

Khan (29-3, 19 KOs) credited his work with new trainer Virgil Hunter with helping him to deal with Collazo’s southpaw style.           

“He taught me some good things and we put them together. It was a good thing because Collazo was tough. He’s really awkward,” Khan said.

Khan, 30, hadn’t been in the ring in over a year, having turned down a match with Devon Alexander for the IBF welterweight championship in December in order to wait on a match with Mayweather. After Mayweather snubbed him in favor of Maidana, Khan was offered a spot in the co-feature against Collazo, who blasted his way on the card with a fourth round KO of Victor Ortiz in January.

Before taking off such a long time from the ring, Khan of Bolton, England had been on an incredible pace that made him one of boxing’s rising stars. During a two year span (2010-12), five of Khan’s six opponents were either world champions or former world champions – Marcos Maidana, Paulie Malignaggi, Zab Judah, Lamont Peterson and Danny Garcia.

Khan was moving up to welterweight for the first time. He spent the last eight months with Hunter preparing to fight at the new weight. He said he didn’t think would be a problem and he wasn’t concerned about matching up with Collazo, who wasn’t noted for his punching power until he drilled Ortiz.

Khan took the first round to determine just how much sting Collazo had on his punches. After he determined that he could take a good shot from the former welterweight champion, Khan began to open up and unleash his offense in the second round. Even though Collazo, a southpaw, had an awkward style and presented a difficult target, Khan still found a home for his left hook.

Khan dropped Collazo with a short, straight right hand in the fourth round and later caught him with a shot behind the head that buckled Collazo’s legs.  Collazo, sensing that he needed to make it a fire-fight to win, dropped his hands and tried to bait Khan into coming forward. But Khan wasn’t biting. He was doing just fine boxing.

Khan was getting the best of Collazo in the exchanges. At one point during a clinch in the seventh round Collazo hit Khan low on the right thigh and referee Vic Drakulich warned him for the shot below the border. When the round ended Khan had some choice words for Collazo.

Early in the eighth round Collazo hit Khan long again. This time Drakulich took away a point from Collazo for the foul.  Collazo stunned Khan with a left hook that had him wobbling around the ring. Khan tried to keep from getting hit with that shot again and started to clamp down on Collazo’s arms in the clinch. He did it once too often and Drakulich deducted a point form him for excessive holding.

Sensing that he was trailing in the fight, Collazo started to pick up the pressure and the pace on Khan in the ninth round. That pressure didn’t work, because Khan reacted by picking up his pace.

In the 10^th round Khan opened up with a blistering combination on Collazo, pinning him on the ropes and landing rights and lefts in succession. At the end of one of those barrages, Khan landed a left to the chin that dropped Collazo in the corner. Collazo stayed on one knee until the count reached seven and got up. Khan went to work on him again and this time he landed a left-right combination on Collazo’s jaw that sent him to the canvas again. Collazo managed to weather the storm and finished the round on his feet.

In the 12^th round Collazo landed a low blow that buckled Khan’s knees and sent him to the canvas. Khan got up, but went back down to one knee. Drakulich gave him time to shake it off and then he went back to work on Collazo, who was bleeding from the mouth, along the bridge of his nose and from a small cut under his left eye.          

It was a tough night for Collazo, who was experiencing a career rebirth following the victory over Ortiz. He had suffered some disappointing and controversial losses to Hatton and Berto, before getting soundly beaten by Mosley.

And on Saturday night he came up short again in one of the biggest fights of his life. But this time there was no questions about it.