Competition at the 2013 UCI BMX World Championships began Wednesday at the Vector Arena in Auckland, New Zealand, with the challenge class races. Michael Gonzales (Watsonville, Calif.) topped the 14-year-old boys podium while Colin Hudson (Longmont, Colo./Factory Crupi) won the 16-year-old boys category. In all, the United States registered eight top-three results, including gold medals for Gonzales and Hudson.