Olympics-Athletics-Dalilah Muhammad of U.S. wins women's 400m hurdles

By Mark Trevelyan RIO DE JANEIRO, Aug 18 (Reuters) - Dalilah Muhammad of the United States led from start to finish to take the gold medal on Thursday in the women's Olympic 400 metres hurdles. Denmark's Sara Slott Petersen won the silver medal ahead of Ashley Spencer of the United States, with world champion Zuzana Hejnova of the Czech Republic managing only fourth. With steady rain pouring down at the Olympic stadium, Muhammad shot out of the blocks, rose quickest at the first hurdle and never looked like being overtaken. She clocked 53.13 seconds to win by a margin of 0.42. (Reporting by Mark Trevelyan, editing by Mitch Phillips)