Titmus wins duel in the pool as Dressel launches Olympic gold rush

Australia's Ariarne Titmus won a thrilling 400m freestyle duel with American great Katie Ledecky in the Olympic pool on Monday as Caeleb Dressel launched his bid for a seven-gold spree in style. It could be the start of a seven-title spree for Dressel, 24, whose 13 world titles have prompted inevitable comparisons with Phelps -- winner of eight golds in 2008 and 23 in total.