In the second round, Katsidis seemingly scored a knockdown due to a cuffing left hook, but this was not counted by referee Russell Mora. In the fourth, both fighters exchanged punches wildly, with Guerrero maintaining the upper hand. A hard straight left from Guerrero wobbled Katsidis in round five and had him hurt for the remainder of the round. As the fight wore on, Katsidis would lose two points in the eighth round because of repeated low blows; Guerrero also lost a point for the same reason in the ninth. With all twelve rounds completed, the judges were unanimous in scoring 118–107, 118–106 and 117–108 for Guerrero.