Olympics-Athletics-Jamaica throw down 4x400 gauntlet to U.S. men

By Mitch Phillips RIO DE JANEIRO, Aug 19 (Reuters) - Jamaica might have dominated the short sprints and relays in the last few Olympics but they have never won the men's 4x400 metres - something they hope to change on Saturday after edging out the U.S. in their semi-final on Friday. Jamaica have not even medalled in the race since claiming a silver in 2000 but clocked two minutes 58.29 to beat their big rivals on the line. The U.S., stunned by Bahamas four years ago but always the team to beat, have plenty of fresh blood to come in and will start as favourites. Britain won the second heat impressively ahead of Belgium and defending champions Bahamas but were then disqualified, allowing Brazil to slip into the final by the back door Poland, Cuba and outsiders Botswana also progressed but Trinidad and Tobago were also disqualified after originally finishing in a qualifying position in the first heat. (Editing by Ed Osmond)