score a knockdown as well as scoring enough points to win by split decision, leaving the belt vacant. Light welterweight Guzman's well documented struggles to make the 135 lb lightweight limit prompted him to move to junior welterweight. His first bout at 140 lbs against Jason Davis took place on the undercard of Amir Khan vs. Marcos Maidana on December 11 at the Mandalay Bay Resort & Casino in Las Vegas. The bout was ended by TKO in just the second round in the favour of Guzman, although he notably failed to make the weight for the second consecutive bout, coming in at 144.5 lbs Positive testing drug controversy In the post-fight drug test after the bout against Davis, however, Guzman tested positive for Furosemide, a diuretic banned by the Nevada State Athletic Commission, and the same kind used by Ali Funeka who was suspended for nine months after the rematch with Guzman. As a penalty, Guzman was suspended from boxing for eight months and his latest victory was turned into a no-contest. After complying with an eight-month suspension for, admittedly, having used a diuretic in an attempt to make weight for his fight against Jason Davis in December, 2010; Joan Guzman returned to the ring at 140 lbs. (Super lightweight) in his homeland, Dominican Republic, against Colombian Florencio Castellano in January 2012. Guzman knocked out Castellano in the first round, roughly 2:59 minutes into it. It was his first fight under the roster of Acquinity Sports (now Iron Mike Productions), a Florida-based promotion company, which has bet on the athlete's talent; and his first knock-out in at least ten fights(Excluding Davis's turned no-contest). On March 2, 2012, Guzman faced Puerto Rican Jesus Pabón. The fight was presented as the main event at ESPN2's Friday Night Fights. The event was named 'D-Day Dominican Domination' and featured several Dominican boxers, including Ed 'The Lion' Paredes and Juan Carlos Payano. Guzman came in for the first official weigh-in a quarter-pound heavier than the mandatory 140 lbs., needing two more attempts to finally make weight. However, Joan seemed pretty strong at 140. He knocked down Pabon in the very first round with a left hook; followed by consecutive knock-downs in the second and third rounds. Although Joan dominated all rounds, critics complained about his lack of 'killer instinct' and his showboating, which they say the ex-titlist might have used to hide the fact