p>American Gretchen Walsh broke her own 100m butterfly world record on Saturday, clocking 55.09sec in the heats at the Tyr Pro Swim Series meeting in Orlando, Florida. Walsh had set the previous world record of 55.18sec at the US Olympic trials in Indianapolis on June 15 last year, although she settled for silver in the event at the Paris Olympics behind teammate Torri Huske. Walsh's record came a day after the two-time Olympic relay gold medallist joined Sweden's Sarah Sjostrom as the only women to break 25 seconds for the 50m butterfly, clocking 24.93 to win the final.(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)