Oliva for the vacant WBO's world super bantamweight title on August 17, 2002. Guzmán won the championship with a 3rd-round knockout win. Sánchez returned to boxing and at last fought Guzmán on February 26, 2004, in San Diego, California. Guzmán retained the title, knocking out the former world champion in seven rounds. He later defended that title, defeating previously unbeaten Fernando Beltrán by unanimous decision on April 22, 2005. Following his impressive victory, Guzmán moved to the super featherweight division. At the weigh-in before his scheduled fight for the WBO super featherweight title on September 16, 2006, the title holder, Jorge Rodrigo Barrios, was overweight was eventually stripped of the WBO super featherweight title. Guzman then won the fight and the title by split decision. Guzman then defended his new title with wins over contender Antonio Davis on December 18, 2006, and future two division champion Humberto Soto on November 17, 2007, both by unanimous decision. Move to lightweight In May 2008, Guzman elected to vacate his WBO super featherweight title in order to continue his career in the lightweight division. He was supposed to fight for Nate Campbell's unified WBA super, WBO and IBF titles, on September 13, 2008. Disappointingly, he came in 3½ pounds over the 135 lb. limit. Thus, the fight was cancelled and Guzman was rushed to a hospital after experiencing dehydration and coughing blood. A dismayed Campbell who went through such trouble to fight him, branded Guzman's pull-out as an unprofessional gesture. With regards to his failure, Guzman issued an apology to his fans, people surrounding the scheduled bout, and to Campbell in particular. On December 20, 2008, Guzman took on Ameth Diaz for the WBA lightweight title eliminator. Unlike his bout with Campbell, Guzman successfully made the weight limit. Guzman won his first-ever match as a lightweight by unanimous decision. In an attempt to win a world title at a third weight division, Guzman challenged well regarded Ali Funeka on November 28, 2009, for the vacant IBF lightweight title. Unfortunately for both fighters, the bout resulted in a majority draw which most believed Funeka won by a wide margin. Guzman and Funeka fought again on March 27, 2010, for the same championship. This time however, only Funeka had a chance to win the title as Guzman was 9 pounds above the lightweight limit. Nevertheless, the bout went on as scheduled. There, Guzman managed to