Great Britain's Ellen Gandy is through to the 100m butterfly final after finishing fifth in a rapid second semi-final.
American Dana Vollmer took the win in the same heat with 56.36, just 0.3s off world record pace, with Australia's Alicia Coutts the only other athlete swimming under 57 seconds with a 56.85.
Fran Halsall swum in the first heat, but could only manage seventh, way off the pace set by the two favourites Vollmer and Coutts.
Sweden's Sarah Sjostrom won the first heat with a time of 57.27, only the fourth-fastest semi-final time in all.
