Williams failed to build on his global debut and his career went into decline in the 2008 season. He was eliminated in the 2008 United States Olympic Trials at the quarter-finals stage and recorded a season's best of 49.75 seconds for fourth at the adidas Track Classic. He ranked outside the top 50 that year and never ran as fast again. He placed in the world top fifty for the last time in 2009, with a time of 49.77 seconds.