But , lying second at halfway in Monday 's semifinal , Peirsol miscalculated on the second length to find himself in fourth in 53.22 seconds and ninth overall -- missing out on a final place . Sarah Sjostrom fails to qualify for the final of the 100m breaststroke backstroke in Rome . The defending champion and world record holder only ninth fastest in semifinal . Teenager Sarah Sjostrom sets third 56.06 m butterfly world record in under 52 seconds .
Sarah Sjostrom fails to qualify for the final of the 100m breaststroke backstroke in Rome . The defending champion and world record holder only ninth fastest in semifinal . Teenager Sarah Sjostrom sets third 56.06 m butterfly world record in under 52 seconds .