Khan defeats Collazo in welterweight bout
Amir Khan connects with a right to Luis Collazo during their welterweight bout at the MGM Grand Garden Arena on May 3, 2014 in Las Vegas, Nevada - by Harry How
The 27-year-old Khan, who was fighting for the first time after a 12-month layoff, knocked Collazo down three times in the non-title fight at the MGM Grand Hotel.
Khan looked impressive in the 147-pound (67 kg) division debut, winning on all three judges' scorecards.
Two judges scored it 119-104 while the other had it 117-106.
Khan knocked Collazo down for the first time in the fourth round and then twice in the 10th round.
Khan, a former light welterweight world champion, weighed 161 pounds when he stepped into the ring on Saturday, 14 pounds over his weight at Friday's weigh-in.
Collazo weighed 16 pounds more than his 147 pound weigh-in weight.
The bout was on the undercard of the Floyd Mayweather-Marcos Maidana welterweight unification title fight.