Katie Ledecky made a powerful start in her highly anticipated duel with Ariarne Titmus, setting the fastest time in the women’s 400-meter freestyle preliminaries as the swimming events kicked off at the Paris Olympics on Saturday. Katie Ledecky faced off against rival Australian Ariarne TitmusLedecky secured the coveted No. 4 lane for the evening final with a time of 4:02.19, gearing up for one of the most exciting races of the games. Australian star Ariarne Titmus, known as “The Terminator,” started strong but couldn’t keep up with Ledecky’s surge in the final lap, finishing with the second-f…