Prior to the 2008 Summer Olympics in Beijing, Blas had found success at the international level in judo, having earned a bronze medal at the 2003 and 2007 Pacific Games, and was considered a household name in Guam. Going into the men's heavyweight event at the Games he had placed seventh in the +100 kg category at the 2007 World Judo Championships. He had also been selected as the flagbearer for his nation's six-member delegation. At the officially recorded weight of he was the heaviest competitor not only at the Beijing Olympics, but most likely at any modern Olympic Games, as he surpassed the previous Olympic weight record by . He lost his first bout against Lasha Gujejiani of Georgia, suffering a penalty for stalling, and later claimed that he simply "froze up". He qualified for the repechage because Gujejiani reached the semifinals of the main competition, but was defeated by Daniel McCormick of the United States, having been penalized again, this time for stepping out of bounds in the final 30 seconds. In 2009 he placed second, behind Cedric Medeuf of France in the men's +100 kg event at that year's U.S. Open.